| Description |
The CopyTo method takes all elements from the current Queue and overlays these values onto elements of the TargetArray.
The overlay starts at the TargetIndex value.
Important : the TargetArray must be created in advance - the CopyTo method overlays - it does not build. Also, the target array must have at least the same capacity as the number of elements being overlaid (copied).
Important : the TargetArray data type must be able to accomodate the Queue data types in the copy process. If the CopyTo method cannot cast to the target array, then an exception is thrown.
Just like Clone, CopyTo performs a shallow copy. When the current Queue holds reference (non primitive) data types, the target array element values still refer to the same objects that current queue elements refer to. This is what is referred to as a shallow copy. A deep copy would create new versions of the referred objects.
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| Microsoft MSDN Links |
System.Collections
System.Collections.Queue
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| Copying the whole Queue onto the middle of an Array |
program Project1;
{$APPTYPE CONSOLE}
uses
System.Collections;
var
MyQueue : System.Collections.Queue;
MyArray : System.Array;
i : Integer;
begin
// Create our queue
MyQueue := Queue.Create;
// Add entries to the queue
MyQueue.EnQueue('First');
MyQueue.EnQueue('Second');
MyQueue.Enqueue('Third');
// Create the target array
MyArray := System.Array.CreateInstance(TypeOf(String), 7);
// And fill it
MyArray.SetValue('0.', 0);
MyArray.SetValue('1.', 1);
MyArray.SetValue('2.', 2);
MyArray.SetValue('3.', 3);
MyArray.SetValue('4.', 4);
MyArray.SetValue('5.', 5);
MyArray.SetValue('6.', 6);
// Copy the queue to the middle of the array
MyQueue.CopyTo(MyArray, 2);
// Display the array
Console.WriteLine('MyArray now holds :');
Console.WriteLine;
for i := 0 to MyArray.Length-1 do
Console.WriteLine(MyArray.GetValue(i).toString);
Console.Readline;
end.
| | Show full unit code | MyArray now holds :
0.
1.
First
Second
Third
5.
6.
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