ali643
چهارشنبه 06 اسفند 1382, 14:10 عصر
تابع قدر مطلق
function Abs ( Number : Numeric type ) : Numeric type;
مثال
var
float, bigFloat : single;
int : Integer;
varVar : Variant;
begin
float := -1.5; // Small negative floating point number
bigFloat := -4.56E100; // Infinite negative floating point number
int := -7; // Negative integer
varVar := '-98'; // Variants are converted to floating point!
ShowMessage('Abs(float) = '+FloatToStr(Abs(float)));
ShowMessage('Abs(bigFloat) = '+FloatToStr(Abs(bigFloat)));
ShowMessage('Abs(int) = '+FloatToStr(Abs(int)));
// Variants are converted into Extended floating types
float := Abs(varVar);
ShowMessage('Abs(varVar) = '+FloatToStr(float));
end;
تابع Addr
1 function Addr ( Variable name ) : Pointer;
2 function Addr ( Function name ) : Pointer;
3 function Addr ( Procedure name ) : Pointer;
مثال
var
myString : string;
ptrString : PString;
begin
// Set up variable values
myString := 'Hello there';
ptrString := Addr(myString);
ShowMessage('myString : '+ptrString^);
end;
تابع Arctan
function ArcTan ( const Number : Extended ) : Extended;
مثال
var
float : single;
begin
// The ArcTan of PI/2 should give 1.0
float := ArcTan(PI/2);
ShowMessage('ArcTan of PI/2 = '+FloatToStr(float));
end;
تابع Assigned
1 function Assigned ( PointerName : Pointer ) : Boolean;
2 function Assigned ( ObjectName : TObject ) : Boolean;
3 function Assigned ( MethodName : Method ) : Boolean;
مثال
var
myPtr : PChar;
begin
// Pointer variables are not set to nil by default
if Assigned(myPtr)
then ShowMessage('myPtr is not nil')
else ShowMessage('myPtr is nil');
// So we must set them to nil to be sure that they are undefined
myPtr := Nil;
if Assigned(myPtr)
then ShowMessage('myPtr is still not nil')
else ShowMessage('myPtr is nil');
end;
تابع BeginThread
function BeginThread ( SecurityAttr : Pointer; StackSize : LongWord; ThreadFunc : TThreadFunc; Param : Pointer; CreateFlags : LongWord; var ThreadId : LongWord ) : Integer;
مثال
تمام یونیت
unit Unit1;
interface
uses
Forms, Dialogs, Windows, SysUtils;
type
TMsgRecord = record
thread : Integer;
msg : string[30];
end;
TForm1 = class(TForm)
procedure FormCreate(Sender: TObject);
end;
var
Form1: TForm1;
Implementation
{$R *.dfm} // Include form definitions
ThreadVar // We must allow each thread its own instances
// of the passed record variable
msgPtr : ^TMsgRecord;
// Private thread procedure to show a string
function ShowMsg(Parameter : Pointer) : Integer;
begin
// Set up a 0 return value
Result := 0;
// Map the pointer to the passed data
// Note that each thread has a separate copy of msgPtr
msgPtr := Parameter;
// Display this message
ShowMessagePos('Thread '+IntToStr(msgPtr.thread)+' '+msgPtr.msg,
200*msgPtr.thread, 100);
// End the thread
EndThread(0);
end;
procedure TForm1.FormCreate(Sender: TObject);
var
id1, id2 : LongWord;
thread1, thread2 : Integer;
msg1, msg2 : TMsgRecord;
begin
// set up our display messages
msg1.thread := 1;
msg1.msg := 'Hello World';
msg2.thread := 2;
msg2.msg := 'Goodbye World';
// Start the first thread running asking for users first name
thread1 := BeginThread(nil,
0,
Addr(ShowMsg),
Addr(msg1),
0,
id1);
// And also ask for the surname
thread2 := BeginThread(nil,
0,
Addr(ShowMsg),
Addr(msg2),
0,
id2);
// Ensure that the threads are only closed when all done
ShowMessagePos('Press this when other dialogs finished.', 200, 300);
// Finally, tidy up by closing the threads
CloseHandle(thread1);
CloseHandle(thread2);
end;
end.
تابع Chr
1 function Chr ( IntValue : Integer ) : AnsiChar;
2 function Chr ( IntValue : Integer ) : WideChar;
مثال
var
tab : char;
crlf : string;
begin
// Show the use of Chr
tab := Chr(9);
crlf := Chr(13)+Chr(10);
ShowMessage('Hello'+tab+'World');
ShowMessage('');
ShowMessage('Hello'+crlf+'World');
ShowMessage('');
// Show the equivalent use of ^
tab := ^I; // I = 9th capital of the alphabet
crlf := ^M^J; // M = 13th, J = 10th letters
ShowMessage('Hello'+tab+'World');
ShowMessage('');
ShowMessage('Hello'+crlf+'World');
end;
تابع Copy
1 function Copy ( Source : string; StartChar, Count : Integer ) : string;
2 function Copy ( Source : array; StartIndex, Count : Integer ) : array;
مثال String copy
var
Source, Target : string;
begin
Source := '12345678';
Target := Copy(Source, 3, 4);
ShowMessage('Target : '+Target);
end;
مثال Array copy
var
i : Integer;
Source, Target : array of Integer;
begin
SetLength(Source, 8);
for i := 1 to 8 do // Build the dynamic source array
Source[i-1] := i; // Remember that arrays start at index 0
Target := Copy(Source, 3, 4);
for i := 0 to Length(Target) -1 do // Display the created array
ShowMessage('Target['+IntToStr(i)+'] : '+IntToStr(Target[i]));
end;
تابع Cos
function Cos ( const Number : Extended ) : Extended;
مثال
var
float : single;
begin
// The Sine of 60 degrees = 0.5
float := Cos(PI/3); // = 180/3 = 60 degrees
ShowMessage('Cos(PI/3) = '+FloatToStr(float));
end;
تابع Eof
function Eof ( var FileHandle : TextFile ) ;
مثال
var
myFile : TextFile;
text : string;
begin
// Try to open the Test.txt file for writing to
AssignFile(myFile, 'Test.txt');
ReWrite(myFile);
// Write a couple of well known words to this file
WriteLn(myFile, 'Hello');
WriteLn(myFile, 'World');
// Close the file
CloseFile(myFile);
// Reopen the file in read only mode
Reset(myFile);
// Display the file contents
while not Eof(myFile) do
begin
ReadLn(myFile, text);
ShowMessage(text);
end;
// Close the file for the last time
CloseFile(myFile);
end;
تابع Eoln
function Eoln ( var FileHandle : TextFile ) : Boolean;
مثال
var
myFile : TextFile;
letter : char;
text : string;
begin
// Try to open the Test.txt file for writing to
AssignFile(myFile, 'Test.txt');
ReWrite(myFile);
// Write lines of text to the file
WriteLn(myFile, 'Hello');
WriteLn(myFile, 'To you');
// Close the file
CloseFile(myFile);
// Reopen the file for reading
Reset(myFile);
// Display the file contents
while not Eof(myFile) do
begin
// Proces one line at a time
ShowMessage('Start of a new line :');
while not Eoln(myFile) do
begin
Read(myFile, letter); // Read and display one letter at a time
ShowMessage(letter);
end;
ReadLn(myFile, text);
end;
// Close the file for the last time
CloseFile(myFile);
end;
تابع Exp
function Exp ( Number : Extended ) : Extended;
مثال
var
float : Double;
begin
// Get the natural logarithm of 2
float := Ln(2);
// Show this value
ShowMessage('Ln(2) = '+FloatToStr(float));
// Get the exponent of this value - reverses the Ln operation
float := Exp(float);
// Show this value
ShowMessage('Exp(Ln(2)) = '+FloatToStr(float));
end;
تابع FilePos
1 function FilePos ( var FileHandle : File; ) : LongInt;
2 function FilePos ( car FileHandle : TextFile; ) ;
مثال
var
myWord, myWord1, myWord2, myWord3 : Word;
myFile : File of Word;
begin
// Try to open the Test.cus binary file in write only mode
AssignFile(myFile, 'Test.cus');
ReWrite(myFile);
// Write a few lines of Word data to the file
myWord1 := 123;
myWord2 := 456;
myWord3 := 789;
Write(myFile, myWord1, myWord2, myWord3);
// Close the file
CloseFile(myFile);
// Reopen the file in read only mode
FileMode := fmOpenRead;
Reset(myFile);
// Display the file contents
while not Eof(myFile) do
begin
Read(myFile, myWord);
// Note - FilePos shows the after read position
ShowMessage('Record '+
IntToStr(FilePos(myFile))+' = '+
IntToStr(myWord));
end;
// Close the file for the last time
CloseFile(myFile);
end;
تابع FileSize
function FileSize ( var FileHandle : File; ) : Integer;
مثال
var
myWord, myWord1, myWord2, myWord3 : Word;
myFile : File of Word;
begin
// Try to open the Test.cus binary file in write only mode
AssignFile(myFile, 'Test.cus');
ReWrite(myFile);
// Before writing to the file, show the file size
ShowMessage('File size = '+IntToStr(FileSize(myFile)));
// Write a few lines of Word data to the file
myWord1 := 123;
myWord2 := 456;
myWord3 := 789;
Write(myFile, myWord1, myWord2, myWord3);
// Before closing the file, show the new file size
ShowMessage('File size now = '+IntToStr(FileSize(myFile)));
// Close the file
CloseFile(myFile);
end;
تابع Frac
function Frac ( const Number : Extended ) : Extended;
مثال
begin
ShowMessage('Round(12.75) = '+IntToStr(Round(12.75)));
ShowMessage('Trunc(12.75) = '+IntToStr(Trunc(12.75)));
ShowMessage(' Int(12.75) = '+FloatToStr(Int(12.75)));
ShowMessage(' Frac(12.75) = '+FloatToStr(Frac(12.75)));
end;
تابع GetLastError
function GetLastError : Integer;
مثال
begin
if DeleteFile('CanDeletMe.txt')
then ShowMessage('File deleted OK')
else ShowMessage('File not deleted, error code = '+
IntToStr(GetLastError));
end;
تابع GetMem
function GetMem ( var StoragePointer : Pointer; StorageSize : Integer ) ;
مثال
type
TRecord = Record
name : string[10];
age : Byte;
end;
var
recPointer : ^TRecord;
begin
// Allocate storage for three records
// Note : It is better to use New for this
// It is used here for illustration purposes only
GetMem(recPointer, 3 * SizeOf(TRecord));
// Fill out these 3 records with values
recPointer.name := 'Brian';
recPointer.age := 23;
Inc(recPointer);
recPointer.name := 'Jim';
recPointer.age := 55;
Inc(recPointer);
recPointer.name := 'Sally';
recPointer.age := 38;
// Now display these values
Dec(recPointer, 2);
ShowMessageFmt('%s is %d',[recPointer.name, recPointer.age]);
Inc(recPointer);
ShowMessageFmt('%s is %d',[recPointer.name, recPointer.age]);
Inc(recPointer);
ShowMessageFmt('%s is %d',[recPointer.name, recPointer.age]);
end;
تابع Hi
function Hi ( IntValue : Integer ) : Byte;
مثال
var
i : Integer;
begin
i := $2345; // $2345 hex : $23 hi byte, $45 lo byte
ShowMessage(Format('Integer = $%x', [i]));
ShowMessage(Format('Hi byte = $%x', [Hi(i)]));
ShowMessage(Format('Lo byte = $%x', [Lo(i)]));
end;
تابع High
function High ( type or variable ) : Ordinal type;
مثال
type
// Declare character, array and enumerated data types
TChar = char;
TArray = array [3..7] of Integer;
TEnum = (Mon=5, Tue, Wed, Thu, Fri, Sat, Sun);
TShort = shortstring;
var
// Declare variables of the above data types
myChar : TChar;
myArray : TArray;
myEnum : TEnum;
myShort : TShort;
begin
// Show the high values of the types and variables
ShowMessage('High(TChar) = '+IntToStr(Ord(High(TChar))));
ShowMessage('High(myChar) = '+IntToStr(Ord(High(myChar))));
ShowMessage('High(TArray) = '+IntToStr(High(TArray)));
ShowMessage('High(myArray) = '+IntToStr(High(myArray)));
ShowMessage('High(TEnum) = '+IntToStr(Ord(High(TEnum))));
ShowMessage('High(myEnum) = '+IntToStr(Ord(High(myEnum))));
ShowMessage('High(TShort) = '+IntToStr(Ord(High(TShort))));
ShowMessage('High(myShort) = '+IntToStr(Ord(High(myShort))));
end;
تابع Int
function Int ( const Number : Extended ) : Extended;
مثال
begin
ShowMessage('Round(12.75) = '+IntToStr(Round(12.75)));
ShowMessage('Trunc(12.75) = '+IntToStr(Trunc(12.75)));
ShowMessage(' Int(12.75) = '+FloatToStr(Int(12.75)));
ShowMessage(' Frac(12.75) = '+FloatToStr(Frac(12.75)));
end;
تابع IOResult
function IOResult : Integer;
مثال
var
error : Integer;
begin
// Try to create a new subdirectory in the current directory
// Switch off I/O error checking
{$IOChecks off}
MkDir('TempDirectory');
// Did the directory get created OK?
error := IOResult;
if error = 0
then ShowMessage('Directory created OK')
else ShowMessageFmt('Directory creation failed with error %d',[error]);
// Try to create the directory again - this will fail!
MkDir('TempDirectory');
error := IOResult; // Save the return code
if error = 0
then ShowMessage('Directory created OK again')
else ShowMessageFmt('Repeat creation failed with error %d',[error]);
// Delete the directory to tidy up
RmDir('TempDirectory');
// Switch IO checking back on
{$IOChecks on}
end;
تابع IsMultiThread
function IsMultiThread : Boolean;
مثال یونیت کامل
unit Unit1;
interface
uses
Forms, Dialogs, Windows, SysUtils;
type
TMsgRecord = record
msg : string[30];
end;
TForm1 = class(TForm)
procedure FormCreate(Sender: TObject);
end;
var
Form1: TForm1;
Implementation
{$R *.dfm} // Include form definitions
ThreadVar // We must allow each thread its own instances
// of the passed record variable
msgPtr : ^TMsgRecord;
// Private thread procedure to show a string
function ShowMsg(Parameter : Pointer) : Integer;
begin
// Set up a 0 return value
Result := 0;
// Map the pointer to the passed data
// Note that each thread has a separate copy of msgPtr
msgPtr := Parameter;
// Display this message
ShowMessagePos('Thread message : '+msgPtr.msg, 200, 100);
// End the thread
EndThread(0);
end;
procedure TForm1.FormCreate(Sender: TObject);
var
id1 : LongWord;
thread1 : Integer;
msg1 : TMsgRecord;
showMsgFunc : TThreadFunc;
begin
// Set up the thread function
showMsgFunc := Addr(ShowMsg);
// Set up our display messages
msg1.msg := 'Hello World';
// Inidicate that we are not running a thread
if IsMultiThread
then ShowMessage('Multi-threaded')
else ShowMessage('Single threaded');
// Start the first thread running asking for users first name
thread1 := BeginThread(nil,
0,
showMsgFunc,
Addr(msg1),
0,
id1);
// Inidicate that we are running a thread
if IsMultiThread
then ShowMessage('Multi-threaded')
else ShowMessage('Single threaded');
// Ensure that the thread is only closed when all done
ShowMessagePos('Press this when thread dialog finished.', 200, 300);
// Finally, tidy up by closing the threads
CloseHandle(thread1);
end;
end.
تابع Length
1 function Length ( const SourceString : string ) : Integer;
2 function Length ( const SourceArray : array ) : Integer;
مثال
var
openArray : array of char;
fixedArray : array[2..4] of Integer;
multiArray : array[2..4, 1..9] of Integer;
shortStr : shortstring;
longStr : string;
i : Integer;
begin
// Define the length of the open array
SetLength(openArray, 17);
// Show the length of the arrays
ShowMessage('Length of openArray = '+IntToStr(Length(openArray)));
ShowMessage('Length of fixedArray = '+IntToStr(Length(fixedArray)));
ShowMessage('Length of multiArray = '+IntToStr(Length(multiArray)));
// Assign to the strings
shortStr := 'ABCDEFGH';
longStr := '12345678901234567890';
ShowMessage('Length of shortStr = '+IntToStr(Length(shortStr)));
ShowMessage('Length of longStr = '+IntToStr(Length(longStr)));
// Display one letter at a time from the short string
for i := 1 to Length(shortStr) do
ShowMessage('Letter '+IntToStr(i)+' = '+shortStr[i]);
end;
تابع Ln
function Ln ( Number : Extended ) : Extended;
مثال
var
float : Double;
begin
// Get the natural logarithm of 2
float := Ln(2);
// Show this value
ShowMessage('Ln(2) = '+FloatToStr(float));
// Get the exponent of this value - reverses the Ln operation
float := Exp(float);
// Show this value
ShowMessage('Exp(Ln(2)) = '+FloatToStr(float));
end;
تابع Lo
[code] function Lo ( IntValue : Integer ) : Byte;[/code]
مثال
var
i : Integer;
begin
i := $2345; // $2345 hex : $23 hi byte, $45 lo byte
ShowMessage(Format('Integer = $%x', [i]));
ShowMessage(Format('Hi byte = $%x', [Hi(i)]));
ShowMessage(Format('Lo byte = $%x', [Lo(i)]));
end;
تابع
function Low ( type or variable ) : Ordinal type;
مثال
type
// Declare character, array and enumerated data types
TChar = char;
TArray = array [3..7] of Integer;
TEnum = (Mon=5, Tue, Wed, Thu, Fri, Sat, Sun);
TShort = shortstring;
var
// Declare variables of the above data types
myChar : TChar;
myArray : TArray;
myEnum : TEnum;
myShort : TShort;
begin
// Show the low values of the types and variables
ShowMessage('Low(TChar) = '+IntToStr(Ord(Low(TChar))));
ShowMessage('Low(myChar) = '+IntToStr(Ord(Low(myChar))));
ShowMessage('Low(TArray) = '+IntToStr(Low(TArray)));
ShowMessage('Low(myArray) = '+IntToStr(Low(myArray)));
ShowMessage('High(myArray) = '+IntToStr(High(myArray)));
ShowMessage('Low(TEnum) = '+IntToStr(Ord(Low(TEnum))));
ShowMessage('Low(myEnum) = '+IntToStr(Ord(Low(myEnum))));
ShowMessage('High(myEnum) = '+IntToStr(Ord(High(myEnum))));
ShowMessage('Low(TShort) = '+IntToStr(Ord(Low(TShort))));
ShowMessage('Low(myShort) = '+IntToStr(Ord(Low(myShort))));
end;
تابع Odd
function Odd ( Number : Integer | Int64 ) : Boolean;
مثال
var
i : Integer;
begin
// Display all odd numbers in the range 1 to 9
for i := 1 to 9 do
if Odd(i) then ShowMessageFmt('%d is odd',[i]);
end;
تابع Ord
1 function Ord ( Arg : AnsiChar | Char | WideChar | Enumeration | Integer ) : Integer;
2 function Ord ( Arg : Int64 ) : Int64
مثال
var
A : AnsiChar;
C : Char;
W : WideChar;
E : Boolean;
I : Integer;
I64 : Int64;
begin
// Set the ordinal type values
A := 'A';
C := 'C';
W := 'W';
E := True;
I := 22;
I64 := 64;
// And show the value of each
ShowMessage('A = '+IntToStr(Ord(A)));
ShowMessage('C = '+IntToStr(Ord(C)));
ShowMessage('W = '+IntToStr(Ord(W)));
ShowMessage('E = '+IntToStr(Ord(E)));
ShowMessage('I = '+IntToStr(Ord(I)));
ShowMessage('I64 = '+IntToStr(Ord(I64)));
end;
تابع ParamCount
function ParamCount : Integer;
مثال
var
cmd : string;
i : Integer;
begin
// Before running this code, use the Run/parameters menu option
// to set the following command line parameters : -parm1 -parm2
cmd := CmdLine;
ShowMessage(cmd); // Show the execution command + parameters
// How many parameters were passed?
ShowMessage('There are '+IntToStr(ParamCount)+' parameters');
// Show these parameters - note that the 0th parameter is the
// execution command on Windows
for i := 0 to ParamCount do
ShowMessage('Parameter '+IntToStr(i)+' = '+ParamStr(i));
end;
تابع ParamStr
function ParamStr ( ParmIndex : Integer ) : string;
مثال
var
cmd : string;
i : Integer;
begin
// Before running this code, use the Run/parameters menu option
// to set the following command line parameters : -parm1 -parm2
// Show these parameters - note that the 0th parameter is the
// execution command on Windows
for i := 0 to ParamCount do
ShowMessage('Parameter '+IntToStr(i)+' = '+ParamStr(i));
end;
تابع Pi
function Pi : Extended;
مثال
var
myPi : Extended;
diam : Integer;
begin
diam := 10;
// Show circumference and the area of a circle
// with diameter - 10 cm
ShowMessage(' Diameter = '+IntToStr(diam));
ShowMessage('Circumference = '+FloatToStr(Pi*diam));
ShowMessage(' Area = '+FloatToStr(Pi*(diam/2)*(diam/2)));
end;
تابع Pos
function Pos ( const Needle, HayStack : string ) : Integer;
تابع Pred
function Pred ( const Ordinal Value ) : Ordinal type;
مثال
type
TSuit = (Hearts, Clubs, Diamonds, Spades);
var
Character : char;
Number : Integer;
Card : TSuit;
begin
// We can decrement characters
Character := 'B';
ShowMessage('Character : '+Character);
Character := Pred(Character);
ShowMessage('Character-1 : '+Character);
// We can decrement numbers
Number := 23;
ShowMessage('Number : '+IntToStr(Number));
Number := Pred(Number);
ShowMessage('Number-1 : '+IntToStr(Number));
// We can decrement enumerations
Card := Clubs;
ShowMessage('Card starts at Clubs');
Card := Pred(Card);
if Card = Hearts then ShowMessage('Card is now Hearts');
if Card = Clubs then ShowMessage('Card is now Clubs');
if Card = Diamonds then ShowMessage('Card is now Diamonds');
if Card = Spades then ShowMessage('Card is now Spades');
end;
تابع Random
1 function Random : Extended;
2 function Random ( LimitPlusOne : Integer ) : Integer;
مثال
var
float : single;
int : Integer;
i : Integer;
begin
// Get floating point random numbers in the range 0 <= Number < 1.0
for i := 1 to 5 do
begin
float := Random;
ShowMessage('float = '+FloatToStr(float));
end;
ShowMessage('');
// Get an integer random number in the range 1..100
for i := 1 to 5 do
begin
int := 1 + Random(100); // The 100 value gives a range 0..99
ShowMessage('int = '+IntToStr(int));
end;
end;
تابع Round
function Round ( const Number : Extended ) : Int64;
مثال
begin
ShowMessage('Round(12.75) = '+IntToStr(Round(12.75)));
ShowMessage('Trunc(12.75) = '+IntToStr(Trunc(12.75)));
ShowMessage(' Int(12.75) = '+FloatToStr(Int(12.75)));
ShowMessage(' Frac(12.75) = '+FloatToStr(Frac(12.75)));
end;
تابع SeekEof
function SeekEof ( {var FileHandle : File} ) : Boolean;
مثال
var
myFile : TextFile;
number : Integer;
begin
// Try to open the Test.txt file for writing to
AssignFile(myFile, 'Test.txt');
ReWrite(myFile);
// Write numbers in a string
WriteLn(myFile, '1 2 3 4 '); // White space at the end
// Write numbers as separate parameters
WriteLn(myFile, 5, ' ', 6, ' ', 7, ' '); // Results in '5 6 7 ' text
// Close the file
CloseFile(myFile);
// Reopen the file for reading
Reset(myFile);
// Display the file contents
while not SeekEof(myFile) do
begin
// Read numbers one at a time
ShowMessage('Start of a new line');
while not SeekEoln(myFile) do
begin
Read(myFile, number);
ShowMessage(IntToStr(number));
end;
// Now move to the next line
ReadLn(myFile);
end;
// Close the file for the last time
CloseFile(myFile);
end;
تابع SeekEoln
function SeekEoln ( {var FileHandle : File} ) : Boolean;
مثال
var
myFile : TextFile;
number : Integer;
begin
// Try to open the Test.txt file for writing to
AssignFile(myFile, 'Test.txt');
ReWrite(myFile);
// Write numbers in a string
WriteLn(myFile, '1 2 3 4 '); // White space at the end
// Write numbers as separate parameters
WriteLn(myFile, 5, ' ', 6, ' ', 7, ' '); // Results in '5 6 7 ' text
// Close the file
CloseFile(myFile);
// Reopen the file for reading
Reset(myFile);
// Display the file contents
while not SeekEof(myFile) do
begin
// Read numbers one at a time
ShowMessage('Start of a new line');
while not SeekEoln(myFile) do
begin
Read(myFile, number);
ShowMessage(IntToStr(number));
end;
// Now move to the next line
ReadLn(myFile);
end;
// Close the file for the last time
CloseFile(myFile);
end;
تابع Sin
function Sin ( const Number : Extended ) : Extended;
مثال
var
float : single;
begin
// The Sine of 30 degrees = 0.5
float := Sin(PI/6); // = 180/6 = 30 degrees
ShowMessage('Sin(PI/6) = '+FloatToStr(float));
end;
تابع SizeOf
1 function SizeOf ( Variable : Any type ) : Integer;
2 function SizeOf ( Type ) : Integer;
مثال
var
intNumber : Integer;
extNumber : Extended;
sentence : string;
begin
// Display the sizes of a number of data types
ShowMessageFmt(' SizeOf(Integer) = %d',[SizeOf(Integer)]);
ShowMessageFmt('SizeOf(intNumber) = %d',[SizeOf(intNumber)]);
ShowMessageFmt(' SizeOf(Extended) = %d',[SizeOf(Extended)]);
ShowMessageFmt('SizeOf(extNumber) = %d',[SizeOf(extNumber)]);
// String types and variables are pointers to the actual strings
sentence := 'A long sentence, certainly longer than 4';
ShowMessageFmt(' SizeOf(string) = %d',[SizeOf(string)]);
ShowMessageFmt(' SizeOf(sentence) = %d',[SizeOf(sentence)]);
end;
تابع Slice
function Slice ( SourceArray : array; Count : Integer ) : array;
مثال
var
i : Integer;
Source : array[0..4] of Integer;
begin
// Create the source array with 0..4 values for elements 0..4
for i := 0 to 4 do
Source[i] := i;
// Use the Slice command to pass just the first 3 elements of Source as
// an open array to the ShowSlice procedure below.
ShowSlice(Slice(Source, 3));
end;
// Show an array of unknown size - it is passed as an 'Open' array
procedure TForm1.ShowSlice(SubArray : array of Integer);
var
i : Integer;
begin
// Show every element of this array
for i := 0 to Length(SubArray)-1 do
ShowMessage('SubArray['+IntToStr(i)+'] : '+ IntToStr(SubArray[i]));
end;
تابع Sqr
1 function Sqr ( Number : Integer ) : Integer;
2 function Sqr ( Number : Int64 ) : Int64;
3 function Sqr ( Number : Extended ) : Extended;
مثال
var
number, squared : Byte;
float : Extended;
begin
// The square of 15 = 225
number := 15;
squared := Sqr(number);
ShowMessageFmt('%d squared = %d',[number, squared]);
// The square of 17 = 289
// But result exceeds byte size, so result = 289 MOD 256 = 33
number := 17;
squared := Sqr(number);
ShowMessageFmt('%d squared = %d (see code above)',[number, squared]);
// The square of infinity is still infinity
float := Infinity;
float := Sqr(float);
ShowMessageFmt('Infinity squared = %f',[float]);
end;
تابع Sqrt
function Sqrt ( Number : Extended ) : Extended;
مثال
var
number, squareRoot : Extended;
begin
// The square root of 225 = 15
number := 225;
squareRoot := Sqrt(number);
ShowMessageFmt('Square root of %f = %f',[number, squareRoot]);
// The square root of 3.456 = 1.859...
number := 3.456;
squareRoot := Sqrt(number);
ShowMessageFmt('Square root of %7.3f = %12.12f',[number, squareRoot]);
// The square root of infinity is still infinity
number := Infinity;
number := Sqrt(number);
ShowMessageFmt('Square root of Infinity = %f',[number]);
end;
تابع StringOfChar ( Re
function StringOfChar ( RepeatCharacter : Char; RepeatCount : Integer ) : string;
مثال
var
text, line : string;
begin
// Write a heading with -'s as underline characters
text := '1.An introduction to life as we know it';
line := StringOfChar('-', Length(text));
// Display our underlined heading
ShowMessage(text);
ShowMessage(line);
end;
تابع StringToWideChar
function StringToWideChar ( const SourceString : string; TargetBuffer : PWideChar; TargetSize : Integer ) : PWideChar;
مثال
var
wideChars : array[0..11] of WideChar;
myString : String;
begin
// Set up our string
myString := 'Hello World';
// Copy to a WideChar format in our array
StringToWideChar(myString, wideChars, 12);
// Show what the copy gave
ShowMessage(WideCharToString(wideChars));
end;
تابع Succ
function Succ ( const Ordinal Value ) : Ordinal type;
مثال
type
TSuit = (Hearts, Clubs, Diamonds, Spades);
var
Character : char;
Number : Integer;
Card : TSuit;
begin
// We can increment characters
Character := 'A';
ShowMessage('Character : '+Character);
Character := Succ(Character);
ShowMessage('Character+1 : '+Character);
// We can increment numbers
Number := 23;
ShowMessage('Number : '+IntToStr(Number));
Number := Succ(Number);
ShowMessage('Number+1 : '+IntToStr(Number));
// We can increment enumerations
Card := Clubs;
ShowMessage('Card starts at Clubs');
Card := Succ(Card);
if Card = Hearts then ShowMessage('Card is now Hearts');
if Card = Clubs then ShowMessage('Card is now Clubs');
if Card = Diamonds then ShowMessage('Card is now Diamonds');
if Card = Spades then ShowMessage('Card is now Spades');
end;
تابع Trunc
function Trunc ( const Number : Extended ) : Integer;
مثال
begin
ShowMessage('Round(12.75) = '+IntToStr(Round(12.75)));
ShowMessage('Trunc(12.75) = '+IntToStr(Trunc(12.75)));
ShowMessage(' Int(12.75) = '+FloatToStr(Int(12.75)));
ShowMessage(' Frac(12.75) = '+FloatToStr(Frac(12.75)));
end;
تابع UpCase
function UpCase ( Letter : Char ) : Char;
مثال
var
lower, upper : char;
begin
// Convert a lower case letter to upper case
lower := 'g';
upper := UpCase(lower);
// Display these letters
ShowMessage('lower = '+lower+' upper = '+upper);
end;
تابع WideCharToString
function WideCharToString ( Source : PWideChar; ) : string;
مثال
var
wideCharArray : array[0..5] of WideChar;
myString : String;
begin
// Set up our WideChar array
wideCharArray[0] := 'H';
wideCharArray[1] := 'e';
wideCharArray[2] := 'l';
wideCharArray[3] := 'l';
wideCharArray[4] := 'o';
wideCharArray[5] := #0; // Terminates WideChar strings
// Copy to a normal string
myString := WideCharToString(wideCharArray);
// Show what the copy gave
ShowMessage(myString);
end;
توضیحات فارسی هر Function رو اگه اساتید کمک کنند همین جا پست می کنم
function Abs ( Number : Numeric type ) : Numeric type;
مثال
var
float, bigFloat : single;
int : Integer;
varVar : Variant;
begin
float := -1.5; // Small negative floating point number
bigFloat := -4.56E100; // Infinite negative floating point number
int := -7; // Negative integer
varVar := '-98'; // Variants are converted to floating point!
ShowMessage('Abs(float) = '+FloatToStr(Abs(float)));
ShowMessage('Abs(bigFloat) = '+FloatToStr(Abs(bigFloat)));
ShowMessage('Abs(int) = '+FloatToStr(Abs(int)));
// Variants are converted into Extended floating types
float := Abs(varVar);
ShowMessage('Abs(varVar) = '+FloatToStr(float));
end;
تابع Addr
1 function Addr ( Variable name ) : Pointer;
2 function Addr ( Function name ) : Pointer;
3 function Addr ( Procedure name ) : Pointer;
مثال
var
myString : string;
ptrString : PString;
begin
// Set up variable values
myString := 'Hello there';
ptrString := Addr(myString);
ShowMessage('myString : '+ptrString^);
end;
تابع Arctan
function ArcTan ( const Number : Extended ) : Extended;
مثال
var
float : single;
begin
// The ArcTan of PI/2 should give 1.0
float := ArcTan(PI/2);
ShowMessage('ArcTan of PI/2 = '+FloatToStr(float));
end;
تابع Assigned
1 function Assigned ( PointerName : Pointer ) : Boolean;
2 function Assigned ( ObjectName : TObject ) : Boolean;
3 function Assigned ( MethodName : Method ) : Boolean;
مثال
var
myPtr : PChar;
begin
// Pointer variables are not set to nil by default
if Assigned(myPtr)
then ShowMessage('myPtr is not nil')
else ShowMessage('myPtr is nil');
// So we must set them to nil to be sure that they are undefined
myPtr := Nil;
if Assigned(myPtr)
then ShowMessage('myPtr is still not nil')
else ShowMessage('myPtr is nil');
end;
تابع BeginThread
function BeginThread ( SecurityAttr : Pointer; StackSize : LongWord; ThreadFunc : TThreadFunc; Param : Pointer; CreateFlags : LongWord; var ThreadId : LongWord ) : Integer;
مثال
تمام یونیت
unit Unit1;
interface
uses
Forms, Dialogs, Windows, SysUtils;
type
TMsgRecord = record
thread : Integer;
msg : string[30];
end;
TForm1 = class(TForm)
procedure FormCreate(Sender: TObject);
end;
var
Form1: TForm1;
Implementation
{$R *.dfm} // Include form definitions
ThreadVar // We must allow each thread its own instances
// of the passed record variable
msgPtr : ^TMsgRecord;
// Private thread procedure to show a string
function ShowMsg(Parameter : Pointer) : Integer;
begin
// Set up a 0 return value
Result := 0;
// Map the pointer to the passed data
// Note that each thread has a separate copy of msgPtr
msgPtr := Parameter;
// Display this message
ShowMessagePos('Thread '+IntToStr(msgPtr.thread)+' '+msgPtr.msg,
200*msgPtr.thread, 100);
// End the thread
EndThread(0);
end;
procedure TForm1.FormCreate(Sender: TObject);
var
id1, id2 : LongWord;
thread1, thread2 : Integer;
msg1, msg2 : TMsgRecord;
begin
// set up our display messages
msg1.thread := 1;
msg1.msg := 'Hello World';
msg2.thread := 2;
msg2.msg := 'Goodbye World';
// Start the first thread running asking for users first name
thread1 := BeginThread(nil,
0,
Addr(ShowMsg),
Addr(msg1),
0,
id1);
// And also ask for the surname
thread2 := BeginThread(nil,
0,
Addr(ShowMsg),
Addr(msg2),
0,
id2);
// Ensure that the threads are only closed when all done
ShowMessagePos('Press this when other dialogs finished.', 200, 300);
// Finally, tidy up by closing the threads
CloseHandle(thread1);
CloseHandle(thread2);
end;
end.
تابع Chr
1 function Chr ( IntValue : Integer ) : AnsiChar;
2 function Chr ( IntValue : Integer ) : WideChar;
مثال
var
tab : char;
crlf : string;
begin
// Show the use of Chr
tab := Chr(9);
crlf := Chr(13)+Chr(10);
ShowMessage('Hello'+tab+'World');
ShowMessage('');
ShowMessage('Hello'+crlf+'World');
ShowMessage('');
// Show the equivalent use of ^
tab := ^I; // I = 9th capital of the alphabet
crlf := ^M^J; // M = 13th, J = 10th letters
ShowMessage('Hello'+tab+'World');
ShowMessage('');
ShowMessage('Hello'+crlf+'World');
end;
تابع Copy
1 function Copy ( Source : string; StartChar, Count : Integer ) : string;
2 function Copy ( Source : array; StartIndex, Count : Integer ) : array;
مثال String copy
var
Source, Target : string;
begin
Source := '12345678';
Target := Copy(Source, 3, 4);
ShowMessage('Target : '+Target);
end;
مثال Array copy
var
i : Integer;
Source, Target : array of Integer;
begin
SetLength(Source, 8);
for i := 1 to 8 do // Build the dynamic source array
Source[i-1] := i; // Remember that arrays start at index 0
Target := Copy(Source, 3, 4);
for i := 0 to Length(Target) -1 do // Display the created array
ShowMessage('Target['+IntToStr(i)+'] : '+IntToStr(Target[i]));
end;
تابع Cos
function Cos ( const Number : Extended ) : Extended;
مثال
var
float : single;
begin
// The Sine of 60 degrees = 0.5
float := Cos(PI/3); // = 180/3 = 60 degrees
ShowMessage('Cos(PI/3) = '+FloatToStr(float));
end;
تابع Eof
function Eof ( var FileHandle : TextFile ) ;
مثال
var
myFile : TextFile;
text : string;
begin
// Try to open the Test.txt file for writing to
AssignFile(myFile, 'Test.txt');
ReWrite(myFile);
// Write a couple of well known words to this file
WriteLn(myFile, 'Hello');
WriteLn(myFile, 'World');
// Close the file
CloseFile(myFile);
// Reopen the file in read only mode
Reset(myFile);
// Display the file contents
while not Eof(myFile) do
begin
ReadLn(myFile, text);
ShowMessage(text);
end;
// Close the file for the last time
CloseFile(myFile);
end;
تابع Eoln
function Eoln ( var FileHandle : TextFile ) : Boolean;
مثال
var
myFile : TextFile;
letter : char;
text : string;
begin
// Try to open the Test.txt file for writing to
AssignFile(myFile, 'Test.txt');
ReWrite(myFile);
// Write lines of text to the file
WriteLn(myFile, 'Hello');
WriteLn(myFile, 'To you');
// Close the file
CloseFile(myFile);
// Reopen the file for reading
Reset(myFile);
// Display the file contents
while not Eof(myFile) do
begin
// Proces one line at a time
ShowMessage('Start of a new line :');
while not Eoln(myFile) do
begin
Read(myFile, letter); // Read and display one letter at a time
ShowMessage(letter);
end;
ReadLn(myFile, text);
end;
// Close the file for the last time
CloseFile(myFile);
end;
تابع Exp
function Exp ( Number : Extended ) : Extended;
مثال
var
float : Double;
begin
// Get the natural logarithm of 2
float := Ln(2);
// Show this value
ShowMessage('Ln(2) = '+FloatToStr(float));
// Get the exponent of this value - reverses the Ln operation
float := Exp(float);
// Show this value
ShowMessage('Exp(Ln(2)) = '+FloatToStr(float));
end;
تابع FilePos
1 function FilePos ( var FileHandle : File; ) : LongInt;
2 function FilePos ( car FileHandle : TextFile; ) ;
مثال
var
myWord, myWord1, myWord2, myWord3 : Word;
myFile : File of Word;
begin
// Try to open the Test.cus binary file in write only mode
AssignFile(myFile, 'Test.cus');
ReWrite(myFile);
// Write a few lines of Word data to the file
myWord1 := 123;
myWord2 := 456;
myWord3 := 789;
Write(myFile, myWord1, myWord2, myWord3);
// Close the file
CloseFile(myFile);
// Reopen the file in read only mode
FileMode := fmOpenRead;
Reset(myFile);
// Display the file contents
while not Eof(myFile) do
begin
Read(myFile, myWord);
// Note - FilePos shows the after read position
ShowMessage('Record '+
IntToStr(FilePos(myFile))+' = '+
IntToStr(myWord));
end;
// Close the file for the last time
CloseFile(myFile);
end;
تابع FileSize
function FileSize ( var FileHandle : File; ) : Integer;
مثال
var
myWord, myWord1, myWord2, myWord3 : Word;
myFile : File of Word;
begin
// Try to open the Test.cus binary file in write only mode
AssignFile(myFile, 'Test.cus');
ReWrite(myFile);
// Before writing to the file, show the file size
ShowMessage('File size = '+IntToStr(FileSize(myFile)));
// Write a few lines of Word data to the file
myWord1 := 123;
myWord2 := 456;
myWord3 := 789;
Write(myFile, myWord1, myWord2, myWord3);
// Before closing the file, show the new file size
ShowMessage('File size now = '+IntToStr(FileSize(myFile)));
// Close the file
CloseFile(myFile);
end;
تابع Frac
function Frac ( const Number : Extended ) : Extended;
مثال
begin
ShowMessage('Round(12.75) = '+IntToStr(Round(12.75)));
ShowMessage('Trunc(12.75) = '+IntToStr(Trunc(12.75)));
ShowMessage(' Int(12.75) = '+FloatToStr(Int(12.75)));
ShowMessage(' Frac(12.75) = '+FloatToStr(Frac(12.75)));
end;
تابع GetLastError
function GetLastError : Integer;
مثال
begin
if DeleteFile('CanDeletMe.txt')
then ShowMessage('File deleted OK')
else ShowMessage('File not deleted, error code = '+
IntToStr(GetLastError));
end;
تابع GetMem
function GetMem ( var StoragePointer : Pointer; StorageSize : Integer ) ;
مثال
type
TRecord = Record
name : string[10];
age : Byte;
end;
var
recPointer : ^TRecord;
begin
// Allocate storage for three records
// Note : It is better to use New for this
// It is used here for illustration purposes only
GetMem(recPointer, 3 * SizeOf(TRecord));
// Fill out these 3 records with values
recPointer.name := 'Brian';
recPointer.age := 23;
Inc(recPointer);
recPointer.name := 'Jim';
recPointer.age := 55;
Inc(recPointer);
recPointer.name := 'Sally';
recPointer.age := 38;
// Now display these values
Dec(recPointer, 2);
ShowMessageFmt('%s is %d',[recPointer.name, recPointer.age]);
Inc(recPointer);
ShowMessageFmt('%s is %d',[recPointer.name, recPointer.age]);
Inc(recPointer);
ShowMessageFmt('%s is %d',[recPointer.name, recPointer.age]);
end;
تابع Hi
function Hi ( IntValue : Integer ) : Byte;
مثال
var
i : Integer;
begin
i := $2345; // $2345 hex : $23 hi byte, $45 lo byte
ShowMessage(Format('Integer = $%x', [i]));
ShowMessage(Format('Hi byte = $%x', [Hi(i)]));
ShowMessage(Format('Lo byte = $%x', [Lo(i)]));
end;
تابع High
function High ( type or variable ) : Ordinal type;
مثال
type
// Declare character, array and enumerated data types
TChar = char;
TArray = array [3..7] of Integer;
TEnum = (Mon=5, Tue, Wed, Thu, Fri, Sat, Sun);
TShort = shortstring;
var
// Declare variables of the above data types
myChar : TChar;
myArray : TArray;
myEnum : TEnum;
myShort : TShort;
begin
// Show the high values of the types and variables
ShowMessage('High(TChar) = '+IntToStr(Ord(High(TChar))));
ShowMessage('High(myChar) = '+IntToStr(Ord(High(myChar))));
ShowMessage('High(TArray) = '+IntToStr(High(TArray)));
ShowMessage('High(myArray) = '+IntToStr(High(myArray)));
ShowMessage('High(TEnum) = '+IntToStr(Ord(High(TEnum))));
ShowMessage('High(myEnum) = '+IntToStr(Ord(High(myEnum))));
ShowMessage('High(TShort) = '+IntToStr(Ord(High(TShort))));
ShowMessage('High(myShort) = '+IntToStr(Ord(High(myShort))));
end;
تابع Int
function Int ( const Number : Extended ) : Extended;
مثال
begin
ShowMessage('Round(12.75) = '+IntToStr(Round(12.75)));
ShowMessage('Trunc(12.75) = '+IntToStr(Trunc(12.75)));
ShowMessage(' Int(12.75) = '+FloatToStr(Int(12.75)));
ShowMessage(' Frac(12.75) = '+FloatToStr(Frac(12.75)));
end;
تابع IOResult
function IOResult : Integer;
مثال
var
error : Integer;
begin
// Try to create a new subdirectory in the current directory
// Switch off I/O error checking
{$IOChecks off}
MkDir('TempDirectory');
// Did the directory get created OK?
error := IOResult;
if error = 0
then ShowMessage('Directory created OK')
else ShowMessageFmt('Directory creation failed with error %d',[error]);
// Try to create the directory again - this will fail!
MkDir('TempDirectory');
error := IOResult; // Save the return code
if error = 0
then ShowMessage('Directory created OK again')
else ShowMessageFmt('Repeat creation failed with error %d',[error]);
// Delete the directory to tidy up
RmDir('TempDirectory');
// Switch IO checking back on
{$IOChecks on}
end;
تابع IsMultiThread
function IsMultiThread : Boolean;
مثال یونیت کامل
unit Unit1;
interface
uses
Forms, Dialogs, Windows, SysUtils;
type
TMsgRecord = record
msg : string[30];
end;
TForm1 = class(TForm)
procedure FormCreate(Sender: TObject);
end;
var
Form1: TForm1;
Implementation
{$R *.dfm} // Include form definitions
ThreadVar // We must allow each thread its own instances
// of the passed record variable
msgPtr : ^TMsgRecord;
// Private thread procedure to show a string
function ShowMsg(Parameter : Pointer) : Integer;
begin
// Set up a 0 return value
Result := 0;
// Map the pointer to the passed data
// Note that each thread has a separate copy of msgPtr
msgPtr := Parameter;
// Display this message
ShowMessagePos('Thread message : '+msgPtr.msg, 200, 100);
// End the thread
EndThread(0);
end;
procedure TForm1.FormCreate(Sender: TObject);
var
id1 : LongWord;
thread1 : Integer;
msg1 : TMsgRecord;
showMsgFunc : TThreadFunc;
begin
// Set up the thread function
showMsgFunc := Addr(ShowMsg);
// Set up our display messages
msg1.msg := 'Hello World';
// Inidicate that we are not running a thread
if IsMultiThread
then ShowMessage('Multi-threaded')
else ShowMessage('Single threaded');
// Start the first thread running asking for users first name
thread1 := BeginThread(nil,
0,
showMsgFunc,
Addr(msg1),
0,
id1);
// Inidicate that we are running a thread
if IsMultiThread
then ShowMessage('Multi-threaded')
else ShowMessage('Single threaded');
// Ensure that the thread is only closed when all done
ShowMessagePos('Press this when thread dialog finished.', 200, 300);
// Finally, tidy up by closing the threads
CloseHandle(thread1);
end;
end.
تابع Length
1 function Length ( const SourceString : string ) : Integer;
2 function Length ( const SourceArray : array ) : Integer;
مثال
var
openArray : array of char;
fixedArray : array[2..4] of Integer;
multiArray : array[2..4, 1..9] of Integer;
shortStr : shortstring;
longStr : string;
i : Integer;
begin
// Define the length of the open array
SetLength(openArray, 17);
// Show the length of the arrays
ShowMessage('Length of openArray = '+IntToStr(Length(openArray)));
ShowMessage('Length of fixedArray = '+IntToStr(Length(fixedArray)));
ShowMessage('Length of multiArray = '+IntToStr(Length(multiArray)));
// Assign to the strings
shortStr := 'ABCDEFGH';
longStr := '12345678901234567890';
ShowMessage('Length of shortStr = '+IntToStr(Length(shortStr)));
ShowMessage('Length of longStr = '+IntToStr(Length(longStr)));
// Display one letter at a time from the short string
for i := 1 to Length(shortStr) do
ShowMessage('Letter '+IntToStr(i)+' = '+shortStr[i]);
end;
تابع Ln
function Ln ( Number : Extended ) : Extended;
مثال
var
float : Double;
begin
// Get the natural logarithm of 2
float := Ln(2);
// Show this value
ShowMessage('Ln(2) = '+FloatToStr(float));
// Get the exponent of this value - reverses the Ln operation
float := Exp(float);
// Show this value
ShowMessage('Exp(Ln(2)) = '+FloatToStr(float));
end;
تابع Lo
[code] function Lo ( IntValue : Integer ) : Byte;[/code]
مثال
var
i : Integer;
begin
i := $2345; // $2345 hex : $23 hi byte, $45 lo byte
ShowMessage(Format('Integer = $%x', [i]));
ShowMessage(Format('Hi byte = $%x', [Hi(i)]));
ShowMessage(Format('Lo byte = $%x', [Lo(i)]));
end;
تابع
function Low ( type or variable ) : Ordinal type;
مثال
type
// Declare character, array and enumerated data types
TChar = char;
TArray = array [3..7] of Integer;
TEnum = (Mon=5, Tue, Wed, Thu, Fri, Sat, Sun);
TShort = shortstring;
var
// Declare variables of the above data types
myChar : TChar;
myArray : TArray;
myEnum : TEnum;
myShort : TShort;
begin
// Show the low values of the types and variables
ShowMessage('Low(TChar) = '+IntToStr(Ord(Low(TChar))));
ShowMessage('Low(myChar) = '+IntToStr(Ord(Low(myChar))));
ShowMessage('Low(TArray) = '+IntToStr(Low(TArray)));
ShowMessage('Low(myArray) = '+IntToStr(Low(myArray)));
ShowMessage('High(myArray) = '+IntToStr(High(myArray)));
ShowMessage('Low(TEnum) = '+IntToStr(Ord(Low(TEnum))));
ShowMessage('Low(myEnum) = '+IntToStr(Ord(Low(myEnum))));
ShowMessage('High(myEnum) = '+IntToStr(Ord(High(myEnum))));
ShowMessage('Low(TShort) = '+IntToStr(Ord(Low(TShort))));
ShowMessage('Low(myShort) = '+IntToStr(Ord(Low(myShort))));
end;
تابع Odd
function Odd ( Number : Integer | Int64 ) : Boolean;
مثال
var
i : Integer;
begin
// Display all odd numbers in the range 1 to 9
for i := 1 to 9 do
if Odd(i) then ShowMessageFmt('%d is odd',[i]);
end;
تابع Ord
1 function Ord ( Arg : AnsiChar | Char | WideChar | Enumeration | Integer ) : Integer;
2 function Ord ( Arg : Int64 ) : Int64
مثال
var
A : AnsiChar;
C : Char;
W : WideChar;
E : Boolean;
I : Integer;
I64 : Int64;
begin
// Set the ordinal type values
A := 'A';
C := 'C';
W := 'W';
E := True;
I := 22;
I64 := 64;
// And show the value of each
ShowMessage('A = '+IntToStr(Ord(A)));
ShowMessage('C = '+IntToStr(Ord(C)));
ShowMessage('W = '+IntToStr(Ord(W)));
ShowMessage('E = '+IntToStr(Ord(E)));
ShowMessage('I = '+IntToStr(Ord(I)));
ShowMessage('I64 = '+IntToStr(Ord(I64)));
end;
تابع ParamCount
function ParamCount : Integer;
مثال
var
cmd : string;
i : Integer;
begin
// Before running this code, use the Run/parameters menu option
// to set the following command line parameters : -parm1 -parm2
cmd := CmdLine;
ShowMessage(cmd); // Show the execution command + parameters
// How many parameters were passed?
ShowMessage('There are '+IntToStr(ParamCount)+' parameters');
// Show these parameters - note that the 0th parameter is the
// execution command on Windows
for i := 0 to ParamCount do
ShowMessage('Parameter '+IntToStr(i)+' = '+ParamStr(i));
end;
تابع ParamStr
function ParamStr ( ParmIndex : Integer ) : string;
مثال
var
cmd : string;
i : Integer;
begin
// Before running this code, use the Run/parameters menu option
// to set the following command line parameters : -parm1 -parm2
// Show these parameters - note that the 0th parameter is the
// execution command on Windows
for i := 0 to ParamCount do
ShowMessage('Parameter '+IntToStr(i)+' = '+ParamStr(i));
end;
تابع Pi
function Pi : Extended;
مثال
var
myPi : Extended;
diam : Integer;
begin
diam := 10;
// Show circumference and the area of a circle
// with diameter - 10 cm
ShowMessage(' Diameter = '+IntToStr(diam));
ShowMessage('Circumference = '+FloatToStr(Pi*diam));
ShowMessage(' Area = '+FloatToStr(Pi*(diam/2)*(diam/2)));
end;
تابع Pos
function Pos ( const Needle, HayStack : string ) : Integer;
تابع Pred
function Pred ( const Ordinal Value ) : Ordinal type;
مثال
type
TSuit = (Hearts, Clubs, Diamonds, Spades);
var
Character : char;
Number : Integer;
Card : TSuit;
begin
// We can decrement characters
Character := 'B';
ShowMessage('Character : '+Character);
Character := Pred(Character);
ShowMessage('Character-1 : '+Character);
// We can decrement numbers
Number := 23;
ShowMessage('Number : '+IntToStr(Number));
Number := Pred(Number);
ShowMessage('Number-1 : '+IntToStr(Number));
// We can decrement enumerations
Card := Clubs;
ShowMessage('Card starts at Clubs');
Card := Pred(Card);
if Card = Hearts then ShowMessage('Card is now Hearts');
if Card = Clubs then ShowMessage('Card is now Clubs');
if Card = Diamonds then ShowMessage('Card is now Diamonds');
if Card = Spades then ShowMessage('Card is now Spades');
end;
تابع Random
1 function Random : Extended;
2 function Random ( LimitPlusOne : Integer ) : Integer;
مثال
var
float : single;
int : Integer;
i : Integer;
begin
// Get floating point random numbers in the range 0 <= Number < 1.0
for i := 1 to 5 do
begin
float := Random;
ShowMessage('float = '+FloatToStr(float));
end;
ShowMessage('');
// Get an integer random number in the range 1..100
for i := 1 to 5 do
begin
int := 1 + Random(100); // The 100 value gives a range 0..99
ShowMessage('int = '+IntToStr(int));
end;
end;
تابع Round
function Round ( const Number : Extended ) : Int64;
مثال
begin
ShowMessage('Round(12.75) = '+IntToStr(Round(12.75)));
ShowMessage('Trunc(12.75) = '+IntToStr(Trunc(12.75)));
ShowMessage(' Int(12.75) = '+FloatToStr(Int(12.75)));
ShowMessage(' Frac(12.75) = '+FloatToStr(Frac(12.75)));
end;
تابع SeekEof
function SeekEof ( {var FileHandle : File} ) : Boolean;
مثال
var
myFile : TextFile;
number : Integer;
begin
// Try to open the Test.txt file for writing to
AssignFile(myFile, 'Test.txt');
ReWrite(myFile);
// Write numbers in a string
WriteLn(myFile, '1 2 3 4 '); // White space at the end
// Write numbers as separate parameters
WriteLn(myFile, 5, ' ', 6, ' ', 7, ' '); // Results in '5 6 7 ' text
// Close the file
CloseFile(myFile);
// Reopen the file for reading
Reset(myFile);
// Display the file contents
while not SeekEof(myFile) do
begin
// Read numbers one at a time
ShowMessage('Start of a new line');
while not SeekEoln(myFile) do
begin
Read(myFile, number);
ShowMessage(IntToStr(number));
end;
// Now move to the next line
ReadLn(myFile);
end;
// Close the file for the last time
CloseFile(myFile);
end;
تابع SeekEoln
function SeekEoln ( {var FileHandle : File} ) : Boolean;
مثال
var
myFile : TextFile;
number : Integer;
begin
// Try to open the Test.txt file for writing to
AssignFile(myFile, 'Test.txt');
ReWrite(myFile);
// Write numbers in a string
WriteLn(myFile, '1 2 3 4 '); // White space at the end
// Write numbers as separate parameters
WriteLn(myFile, 5, ' ', 6, ' ', 7, ' '); // Results in '5 6 7 ' text
// Close the file
CloseFile(myFile);
// Reopen the file for reading
Reset(myFile);
// Display the file contents
while not SeekEof(myFile) do
begin
// Read numbers one at a time
ShowMessage('Start of a new line');
while not SeekEoln(myFile) do
begin
Read(myFile, number);
ShowMessage(IntToStr(number));
end;
// Now move to the next line
ReadLn(myFile);
end;
// Close the file for the last time
CloseFile(myFile);
end;
تابع Sin
function Sin ( const Number : Extended ) : Extended;
مثال
var
float : single;
begin
// The Sine of 30 degrees = 0.5
float := Sin(PI/6); // = 180/6 = 30 degrees
ShowMessage('Sin(PI/6) = '+FloatToStr(float));
end;
تابع SizeOf
1 function SizeOf ( Variable : Any type ) : Integer;
2 function SizeOf ( Type ) : Integer;
مثال
var
intNumber : Integer;
extNumber : Extended;
sentence : string;
begin
// Display the sizes of a number of data types
ShowMessageFmt(' SizeOf(Integer) = %d',[SizeOf(Integer)]);
ShowMessageFmt('SizeOf(intNumber) = %d',[SizeOf(intNumber)]);
ShowMessageFmt(' SizeOf(Extended) = %d',[SizeOf(Extended)]);
ShowMessageFmt('SizeOf(extNumber) = %d',[SizeOf(extNumber)]);
// String types and variables are pointers to the actual strings
sentence := 'A long sentence, certainly longer than 4';
ShowMessageFmt(' SizeOf(string) = %d',[SizeOf(string)]);
ShowMessageFmt(' SizeOf(sentence) = %d',[SizeOf(sentence)]);
end;
تابع Slice
function Slice ( SourceArray : array; Count : Integer ) : array;
مثال
var
i : Integer;
Source : array[0..4] of Integer;
begin
// Create the source array with 0..4 values for elements 0..4
for i := 0 to 4 do
Source[i] := i;
// Use the Slice command to pass just the first 3 elements of Source as
// an open array to the ShowSlice procedure below.
ShowSlice(Slice(Source, 3));
end;
// Show an array of unknown size - it is passed as an 'Open' array
procedure TForm1.ShowSlice(SubArray : array of Integer);
var
i : Integer;
begin
// Show every element of this array
for i := 0 to Length(SubArray)-1 do
ShowMessage('SubArray['+IntToStr(i)+'] : '+ IntToStr(SubArray[i]));
end;
تابع Sqr
1 function Sqr ( Number : Integer ) : Integer;
2 function Sqr ( Number : Int64 ) : Int64;
3 function Sqr ( Number : Extended ) : Extended;
مثال
var
number, squared : Byte;
float : Extended;
begin
// The square of 15 = 225
number := 15;
squared := Sqr(number);
ShowMessageFmt('%d squared = %d',[number, squared]);
// The square of 17 = 289
// But result exceeds byte size, so result = 289 MOD 256 = 33
number := 17;
squared := Sqr(number);
ShowMessageFmt('%d squared = %d (see code above)',[number, squared]);
// The square of infinity is still infinity
float := Infinity;
float := Sqr(float);
ShowMessageFmt('Infinity squared = %f',[float]);
end;
تابع Sqrt
function Sqrt ( Number : Extended ) : Extended;
مثال
var
number, squareRoot : Extended;
begin
// The square root of 225 = 15
number := 225;
squareRoot := Sqrt(number);
ShowMessageFmt('Square root of %f = %f',[number, squareRoot]);
// The square root of 3.456 = 1.859...
number := 3.456;
squareRoot := Sqrt(number);
ShowMessageFmt('Square root of %7.3f = %12.12f',[number, squareRoot]);
// The square root of infinity is still infinity
number := Infinity;
number := Sqrt(number);
ShowMessageFmt('Square root of Infinity = %f',[number]);
end;
تابع StringOfChar ( Re
function StringOfChar ( RepeatCharacter : Char; RepeatCount : Integer ) : string;
مثال
var
text, line : string;
begin
// Write a heading with -'s as underline characters
text := '1.An introduction to life as we know it';
line := StringOfChar('-', Length(text));
// Display our underlined heading
ShowMessage(text);
ShowMessage(line);
end;
تابع StringToWideChar
function StringToWideChar ( const SourceString : string; TargetBuffer : PWideChar; TargetSize : Integer ) : PWideChar;
مثال
var
wideChars : array[0..11] of WideChar;
myString : String;
begin
// Set up our string
myString := 'Hello World';
// Copy to a WideChar format in our array
StringToWideChar(myString, wideChars, 12);
// Show what the copy gave
ShowMessage(WideCharToString(wideChars));
end;
تابع Succ
function Succ ( const Ordinal Value ) : Ordinal type;
مثال
type
TSuit = (Hearts, Clubs, Diamonds, Spades);
var
Character : char;
Number : Integer;
Card : TSuit;
begin
// We can increment characters
Character := 'A';
ShowMessage('Character : '+Character);
Character := Succ(Character);
ShowMessage('Character+1 : '+Character);
// We can increment numbers
Number := 23;
ShowMessage('Number : '+IntToStr(Number));
Number := Succ(Number);
ShowMessage('Number+1 : '+IntToStr(Number));
// We can increment enumerations
Card := Clubs;
ShowMessage('Card starts at Clubs');
Card := Succ(Card);
if Card = Hearts then ShowMessage('Card is now Hearts');
if Card = Clubs then ShowMessage('Card is now Clubs');
if Card = Diamonds then ShowMessage('Card is now Diamonds');
if Card = Spades then ShowMessage('Card is now Spades');
end;
تابع Trunc
function Trunc ( const Number : Extended ) : Integer;
مثال
begin
ShowMessage('Round(12.75) = '+IntToStr(Round(12.75)));
ShowMessage('Trunc(12.75) = '+IntToStr(Trunc(12.75)));
ShowMessage(' Int(12.75) = '+FloatToStr(Int(12.75)));
ShowMessage(' Frac(12.75) = '+FloatToStr(Frac(12.75)));
end;
تابع UpCase
function UpCase ( Letter : Char ) : Char;
مثال
var
lower, upper : char;
begin
// Convert a lower case letter to upper case
lower := 'g';
upper := UpCase(lower);
// Display these letters
ShowMessage('lower = '+lower+' upper = '+upper);
end;
تابع WideCharToString
function WideCharToString ( Source : PWideChar; ) : string;
مثال
var
wideCharArray : array[0..5] of WideChar;
myString : String;
begin
// Set up our WideChar array
wideCharArray[0] := 'H';
wideCharArray[1] := 'e';
wideCharArray[2] := 'l';
wideCharArray[3] := 'l';
wideCharArray[4] := 'o';
wideCharArray[5] := #0; // Terminates WideChar strings
// Copy to a normal string
myString := WideCharToString(wideCharArray);
// Show what the copy gave
ShowMessage(myString);
end;
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