From RAD Studio API Documentation
Jump to: navigation, search


function CharLength(const S: AnsiString; Index: Integer): Integer;


extern DELPHI_PACKAGE int __fastcall CharLength(const System::AnsiString S, int Index)/* overload */;


Type Visibility Source Unit Parent
function public
System.AnsiStrings System.AnsiStrings


Gets the number of bytes required by character.

CharLength returns the number of bytes required by the character in S, starting at Index. If the character does not start at Index, this function returns the size of the remainder of the character, not the full character length.

Note: Index is an element index into S, not a byte or character index.

If the system is not using a multibyte character system (MBCS), CharLength always returns 1.

The following example illustrates CharLength's operation.

  SJISString = type AnsiString(932);

  A: SJISString;
  L: Integer;

  A := 'A' + 'B' + #$82#$A0 + // Japanese Hiragana 'A'
    #$82#$A2 + // Japanese Hiragana 'I'
    #$82#$A4 + // Japanese Hiragana 'U'
    'C' + 'D';

  L := CharLength(A, 1); // returns 1 ('A')
  L := CharLength(A, 2); // returns 1 ('B')
  L := CharLength(A, 3); // returns 2
  L := CharLength(A, 4); // returns 1


In this example, when the index is 1 or 2, it points to the beginning of a single-byte character, so the function returns 1. When the index is 3, it points to the beginning of a two-byte character, and the function returns 2. When the index is 4, it points to the second half of a two-byte character and returns 1. Note that for this example, the element size is 1. Some characters require two elements, and some only need one element.

CharLength can be used to locate the position of multibyte characters in a string.

See Also