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Reference for unit 'System' (#rtl)

IEnumerator

[Properties (by Name)] [Methods (by Name)] [Events (by Name)]

Enumerator support interface

Declaration

Source position: objpash.inc line 250

`type IEnumerator = interface(IInterface)`
`function GetCurrent;`		Returns the current element in the iteration cycle
`function MoveNext;`		Move to the next value
`procedure Reset;`		Reset the pointer
`property Current: TObject; [r]`		Return the current item
`end;`

Inheritance

`IEnumerator`		Enumerator support interface
`IInterface`
?

Description

IEnumerator is the interface needed by the For ... in ... language construct, when operating on classes. It contains all methods that the compiler needs to implement a loop.

A for in loop like the following:

For O in MyObject do
  begin
  // do things
  end;

is treated by the compiler as equivalent to the following code:

Var
  I : IEnumerator;
  O : TObject;
    
begin
  I:=MyObject.GetEnumerator;
  While I.MoveNext do
    begin
    O:=I.GetCurrent;
    // Do things
    end; 
end.

Any class that implements the IEnumerable interface must be able to return an IEnumerator instance for the compiler to use in a For in loop.

IEnumerator

Declaration

Inheritance

Description

See also