System.Val

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Delphi

procedure Val(S: String; var V; var Code: Integer);

Properties

Type	Visibility	Source	Unit	Parent
procedure	public	System.pas	System	System

Description

Converts a string that represents an integer (decimal or hex notation) into a number.

In Delphi code, Val converts the string value S to its numeric representation, as if it were read from a text file with Read. Both $1234 and 0x1234 are the hexadecimal notations supported.

S is a string-type expression; it must be a sequence of characters that form a signed real number, such as "1", "-2" or "+3".

V can be an integer-type or real-type variable.

• If V is an integer-type (integer, Int64, etc.) variable, then S, all characters must be digits; decimal or thousands separators are not supported.
  
• If V is a real-type (Single, Double, etc.) variable, then S, the string, can contain the decimal or thousands separators.

Code is a variable of type Integer.

If the string is invalid, the index of the offending character is stored in Code; otherwise, Code is set to zero. For a null-terminated string, the error position returned in Code is one larger than the actual zero-based index of the character in error.

Example

procedure Test_Val;
var
  LFval: Double;
  LIVal: Integer;
  LCode: Integer;
begin
  // Using integral type
  Val('1234', LIVal, LCode);    // Valid
  if LCode = 0 then
    WriteLn('LIVal = ', LIVal);

  Val('123.456', LIVal, LCode); // Not valid
  if LCode <> 0 then
    WriteLn('LCode = ', LCode);

  // Using floating type
  Val('1234', LFVal, LCode); // Valid
  if LCode = 0 then
    WriteLn('LFVal = ', LFVal);

  Val('123.456', LFVal, LCode); // Valid
  if LCode = 0 then
    WriteLn('LFVal = ', LFVal);
end;

See Also

• System.Str

• Delphi Intrinsic Routines

Code Examples

• SystemVal (Delphi)