October 8, 2000 - Iterating through a Collection

Yehuda Shiran October 8, 2000
Iterating through a Collection
Tips: October 2000

Yehuda Shiran, Ph.D.
Doc JavaScript

Similarly to other OOP languages such as C++, JavaScript supports its own iterator mechanism. It is built on top of the Enumerator object. The Enumerator object provides methods to access items in a collection, by iterating through it. Unlike arrays, you cannot access a specific item of the collection. You have to start iterating from the first item and move through the Enumerator object, one item at a time. You create the Enumerator object by the Enumerator() constructor:

var oEnum = new Enumerator(col);

where col is any valid JavaScript collection, such as document.forms. Here are the methods that this constructor supports:

MethodDescription
moveFirst()Moves to the first item of the enumerator
moveNext()Moves to the next item of the enumerator
item()Returns the current item in the collection
atEnd()Determines whether the enumerator is at the end of the collection