[Overview][Constants][Types][Classes][Procedures and functions][Variables][Index] | Reference for unit 'Objects' (#rtl)

# TCollection.FirstThat

Return first item which matches a test.

## Declaration

Source position: objects.pp line 416

`function TCollection.FirstThat(`
`Test: CodePointer`
`):Pointer;`

## Description

This function returns the first item in the collection for which Test returns a non-nil result. Test is a function that accepts 1 argument: a pointer to an object, and that returns a pointer as a result.

## Errors

None.

## See also

TCollection.LastThat |  | Return last item which matches a test.

## Example

    Program ex21;

    { Program to demonstrate the TCollection.FirstThat method }

    Uses Objects,MyObject; { For TMyObject definition and registration }

    Var C : PCollection;
        M : PMyObject;
        I : Longint;

    Function CheckField (Dummy: Pointer;P : PMyObject) : Longint;

    begin
      If P^.GetField>56 then
        Checkfield:=1
      else
        CheckField:=0;
    end;

    begin
      C:=New(PCollection,Init(100,10));
      For I:=1 to 100 do
        begin
        M:=New(PMyObject,Init);
        M^.SetField(I);
        C^.Insert(M);
        end;
      Writeln ('Inserted ',C^.Count,' objects');
      Writeln ('first one for which Field>56  has index (should be 56) : ',
                C^.IndexOf(C^.FirstThat(@CheckField)));
      C^.FreeAll;
      Dispose(C,Done);
    end.