function StrToIntDef ( const IntegerString : string; Default : Integer ) : Integer;
Description
The StrToIntDef function converts an Integer string, IntegerString such as '123' into an Integer value, with a Default if the conversion fails.
It supports +ve and -ve numbers, and hexadecimal numbers, as prefixed by $ or 0x.
Notes
No conversion errors are generated - bad conversions simply result in the Default being returned.
Related commands
Integer The basic Integer type
IntToStr Convert an integer into a string
StrToInt Convert an integer string into an Integer value
StrToInt64 Convert an integer string into an Int64 value
StrToInt64Def Convert a string into an Int64 value with default
Example code : Converting decimal and hexadecimal numbers
var
A, B, C, D, E, F : Integer;
begin
A := 32;
B := StrToIntDef('100', 0); // '100' string converted to 100 integer
C := StrToIntDef(' -12', 0); // Leading blanks are ignored
D := StrToIntDef('$1E', 0); // Hexadecimal values start with a '$'
E := StrToIntDef('-0x1E', 0); // ... 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 : Integer;
begin
// No need to catch conversion errors
A := StrToIntDef('100 ', 55); // Trailing blanks are not supported
ShowMessage('Value = '+IntToStr(A));
A := StrToIntDef('$FG' , 66); // 'G' is an invalid hexadecimal digit
ShowMessage('Value = '+IntToStr(A));
end;
Show full unit code
Value = 55
Value = 66