The NoRewindIterator class

(PHP 5 >= 5.1.0, PHP 7, PHP 8)

简介

This iterator ignores rewind operations. This allows processing an iterator in multiple partial foreach loops.

类摘要

NoRewindIterator extends IteratorIterator {
/* 方法 */
public __construct ( Iterator $iterator )
public current ( ) : mixed
public getInnerIterator ( ) : iterator
public key ( ) : mixed
public next ( ) : void
public rewind ( ) : void
public valid ( ) : bool
/* 继承的方法 */
public IteratorIterator::__construct ( Traversable $iterator )
public IteratorIterator::current ( ) : mixed
public IteratorIterator::getInnerIterator ( ) : Traversable
public IteratorIterator::key ( ) : mixed
public IteratorIterator::next ( ) : void
public IteratorIterator::rewind ( ) : void
public IteratorIterator::valid ( ) : bool
}

Table of Contents

User Contributed Notes

Anonymous 25-Apr-2020 10:18
As its name implies, NoRewindIterator doesn't invoke the "rewind" method when It reaches the end of the iterator.

Let's demonstrate it by two examles.

In this example the "rewind" method will be invoked after when the "foreache" reaches its end, so, we can repeat printing the same values as many times as we want:

<?PHP
$iterator = new ArrayIterator(['PHP', 'Python', 'Go']);

foreach ($iterator as $item) {
    echo $item.PHP_EOL;
}

foreach ($iterator as $item) {
    echo $item.PHP_EOL;
}
?>

By using the NoRewindIterator, the "rewind" won't be invoked, so, we can't do as we did in previous example:

<?PHP
$iterator = new ArrayIterator(['PHP', 'Python', 'Go']);
$iterator = new NoRewindIterator($iterator);

foreach ($iterator as $item) {
    echo $item.PHP_EOL;
}

// doesn't do anything
foreach ($iterator as $item) {
    echo $item.PHP_EOL;
}

?>