Delphi Basics : StrToInt64 command

DelphiBasics

StrToInt64
Function

Convert an integer string into an Int64 value

SysUtils unit

function StrToInt64(IntegerString string):Int64;

Description

The StrToInt64 function converts an Integer string, IntegerString such as '123' into an Int64 return value.

It supports +ve and -ve numbers, and hexadecimal numbers, as prefixed by $ or 0x.

Notes

The EConvertError exception is thrown if there are errors in IntegerString, such as trailing blanks, decimal points, invalid decimal or hexadecimal characters.

Related commands

Int64		A 64 bit sized integer - the largest in Delphi
IntToStr		Convert an integer into a string
StrToInt		Convert an integer string into an Integer value
StrToInt64Def		Convert a string into an Int64 value with default
StrToIntDef		Convert a string into an Integer value with default

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Example code : Converting decimal and hexadecimal numbers

var
  A, B, C, D, E, F : Int64;

begin
  A := 32;
  B := StrToInt64('100');    // '100' string converted to 100 integer
  C := StrToInt64('  -12');  // Leading blanks are ignored
  D := StrToInt64('$1E');    // Hexadecimal values start with a '$'
  E := StrToInt64('-0x1E');  // ... or with a '0x'
  F := A + B + C + D + E;  // Lets add up all these integers

  ShowMessage('A : '+IntToStr(A));
  ShowMessage('B : '+IntToStr(B));
  ShowMessage('C : '+IntToStr(C));
  ShowMessage('D : '+IntToStr(D));
  ShowMessage('E : '+IntToStr(E));
  ShowMessage('F : '+IntToStr(F));
end;

Show full unit code

  A : 32
  B : 100
  C : -12
  D : 30
  E : -30
  F : 120

Example code : Catching string to integer conversion errors

var
  A : Int64;

begin
  // We will catch conversion errors
  try
    A := StrToInt64('100 ');    // Trailing blanks are not supported
  except
    on Exception : EConvertError do
      ShowMessage(Exception.Message);
  end;

  try
    A := StrToInt64('$FG');    // 'G' is an invalid hexadecimal digit
  except
    on Exception : EConvertError do
      ShowMessage(Exception.Message);
  end;
end;

Show full unit code

'100 ' is not a valid integer value
'$FG' is not a valid integer value