Generics Collections TQueue (Delphi)

Description

This example demonstrates the usage of the generic TQueue class.

Code

var
  Queue: TQueue<String>;

begin
  { Create a new Queue. }
  Queue := TQueue<String>.Create;

  { Enqueue some items to the Queue. }
  Queue.Enqueue('John');
  Queue.Enqueue('Mary');
  Queue.Enqueue('Bob');
  Queue.Enqueue('Anna');
  Queue.Enqueue('Erica');

  { Show the first enqueued element without modifying the Queue. }
  writeln('First enqueued element is: "' + Queue.Peek() + '".');

  { Extract the beginning element: "John". }
  Queue.Extract;

  { Reduce the capacity. }
  Queue.TrimExcess;

  { The remaining count of elements }
  writeln('The queue now contains ' + IntToStr(Queue.Count) + ' elements.');

  { Show the first enqueued element by modifying the Queue. }
  writeln('First enqueued element was: "' + Queue.Dequeue() + '".');

  { Clear the Queue. }
  Queue.Clear;

  { Destroy the Queue completely. }
  Queue.Free;
  readln;

end.

Uses

• System.Generics.Collections.TQueue ( fr | de | ja )
• System.Generics.Collections.TQueue.Enqueue ( fr | de | ja )
• System.Generics.Collections.TQueue.Dequeue ( fr | de | ja )
• System.Generics.Collections.TQueue.Extract ( fr | de | ja )
• System.Generics.Collections.TQueue.Peek ( fr | de | ja )
• System.Generics.Collections.TQueue.TrimExcess ( fr | de | ja )
• System.Generics.Collections.TQueue.Clear ( fr | de | ja )
• System.Generics.Collections.TQueue.Count ( fr | de | ja )

See Also

• Generics Index