Class Iterator

Extends . This interface defines properties and methods for iterating over a collection; it provides the next predicate and the value read-only property. Some Iterators also provide key property values along with each value.

Typical usage is:

 var it = anIterableCollection.iterator;
 while (it.next()) {
   var item = it.value;
 }

Many iterators will signal an error if next is called after the underlying collection has been modified.

To avoid confusion when dealing with Iterables, iterators implement the Iterable.iterator property by just returning themselves.

Constructor Summary Details

Name Description
Iterator()

This is an interface and thus does not have a constructor.

Properties Summary Details

Name, Value Type Description
count
{number}

This read-only property is the total number of items in the iterated collection.

iterator
{Iterator.}

Returns itself, which is convenient for code that expects an Iterable instead of an Iterator.

key

Gets the current index to the item in the collection, assuming next has just returned true.

value
{T}

Gets the current item in the collection, assuming next has just returned true.

Method Summary Details

Name, Return Type Description
all(pred)
{boolean} 1.4

This is true if all invocations of the given predicate on items in the collection are true.More...

Call the given predicate on each item in the collection. As soon as a call returns false, this returns false. Otherwise this returns true. For an empty collection this returns true.

This automatically reset's itself when it is called.

Parameters:
{function(T):boolean} pred
This function must not have any side-effects.
Returns:
{boolean} True if all predicate calls are true; false otherwise.
any(pred)
{boolean} 1.4

This is true if any invocation of the given predicate on items in the collection is true.More...

Call the given predicate on each item in the collection. As soon as a call returns true, this returns true. Otherwise this returns false. For an empty collection this returns false.

This automatically reset's itself when it is called.

Parameters:
{function(T):boolean} pred
This function must not have any side-effects.
Returns:
{boolean} True if any predicate call is true; false otherwise.
each(func)
{Iterator} 1.4

Call the given function on each item in the collection.More...

This automatically reset's itself when it is called.

Parameters:
{function(T)} func
This function must not modify the collection.
Returns:
{Iterator} this iterator itself
first()
{?T} 1.1

Advance if needed to the first item in the collection and return it, or return null if there is none.More...

Caution: this returns a key/value pair, not a value, for Map iterators.

Returns:
{?T}
next()
{boolean}

Call this method to advance the iterator to the next item in the collection.More... This should be called before accessing any value.

Returns:
{boolean} whether another item is available; when true the value of value will be that item.
reset()

Start this iterator all over again.