RecursiveIteratorIterator::__construct

Construct a RecursiveIteratorIterator

&reftitle.description; public `RecursiveIteratorIterator::__construct` `Traversable` `iterator` `int` `mode` RecursiveIteratorIterator::LEAVES_ONLY `int` `flags` 0

Creates a `RecursiveIteratorIterator` from a `RecursiveIterator`.

&reftitle.parameters;

`iterator`

- The iterator being constructed from. Either a `RecursiveIterator` or `IteratorAggregate`.

`mode`

- Optional mode. Possible values are

  - `RecursiveIteratorIterator::LEAVES_ONLY` - The default. Lists only leaves in iteration.
  - `RecursiveIteratorIterator::SELF_FIRST` - Lists leaves and parents in iteration with parents coming first.
  - `RecursiveIteratorIterator::CHILD_FIRST` - Lists leaves and parents in iteration with leaves coming first.

`flags`

- Optional flag. Possible values are `RecursiveIteratorIterator::CATCH_GET_CHILD` which will then ignore exceptions thrown in calls to `RecursiveIteratorIterator::getChildren`.

&reftitle.examples;

### Iterating a RecursiveIteratorIterator

    <?php
    $array = array(
        array(
            array(
                array(
                    'leaf-0-0-0-0',
                    'leaf-0-0-0-1'
                ),
                'leaf-0-0-0'
            ),
            array(
                array(
                    'leaf-0-1-0-0',
                    'leaf-0-1-0-1'
                ),
                'leaf-0-1-0'
            ),
            'leaf-0-0'
        )
    );

    $iterator = new RecursiveIteratorIterator(
        new RecursiveArrayIterator($array),
        $mode
    );
    foreach ($iterator as $key => $leaf) {
        echo "$key => $leaf", PHP_EOL;
    }
    ?>

Output with `$mode = RecursiveIteratorIterator::LEAVES_ONLY`

    0 => leaf-0-0-0-0
    1 => leaf-0-0-0-1
    0 => leaf-0-0-0
    0 => leaf-0-1-0-0
    1 => leaf-0-1-0-1
    0 => leaf-0-1-0
    0 => leaf-0-0

Output with `$mode = RecursiveIteratorIterator::SELF_FIRST`

    0 => Array
    0 => Array
    0 => Array
    0 => leaf-0-0-0-0
    1 => leaf-0-0-0-1
    1 => leaf-0-0-0
    1 => Array
    0 => Array
    0 => leaf-0-1-0-0
    1 => leaf-0-1-0-1
    1 => leaf-0-1-0
    2 => leaf-0-0

Output with `$mode = RecursiveIteratorIterator::CHILD_FIRST`

    0 => leaf-0-0-0-0
    1 => leaf-0-0-0-1
    0 => Array
    1 => leaf-0-0-0
    0 => Array
    0 => leaf-0-1-0-0
    1 => leaf-0-1-0-1
    0 => Array
    1 => leaf-0-1-0
    1 => Array
    2 => leaf-0-0
    0 => Array