Does the Length function applied to an ansistring return (1) the actual length of the string (determined by the position of the null terminator) or (2) the maximum length allocated for the string (recorded in a longint just below the first character)?

Someone told me the answer is (2) and to guarantee getting the actual length, one must use Length (Pchar(s)), where s is an ansistring. Is this true?

Mark

It returns the actual length. The maximumlength is only used for internal householding.

Peter

To clarify: AnsiString is defined as a 'silent' pchar : a pchar that points to :

  @-12 : Longint for maximum size;
  @-8  : Longint for actual size;
  @-4  : Longint for reference count;
  @    : String + Terminating #0;
  Pchar(Ansistring) is a valid typecast.

The length() function returns the actual size of the string, at address @-8. So strlen(pchar(s)) is not needed at all.

@-12 is the memory actually allocated on the heap for this string.

Michael.

And note that it therefore may contain #0's (though whether that is smart is a different subject).

The #0 is for C compability, to allow casting to pchar.