RecursiveArrayIterator::hasChildren

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

RecursiveArrayIterator::hasChildren — Returns whether current entry is an array or an object

说明

public RecursiveArrayIterator::hasChildren ( ) : bool

Returns whether current entry is an array or an object for which an iterator can be obtained via RecursiveArrayIterator::getChildren().

参数

此函数没有参数。

返回值

Returns true if the current entry is an array or an object, otherwise false is returned.

范例

Example #1 RecursiveArrayIterator::hasChildren() example

<?php
$fruits = array("a" => "lemon", "b" => "orange", array("a" => "apple", "p" => "pear"));

$iterator = new RecursiveArrayIterator($fruits);

while ($iterator->valid()) {

    // Check if there are children
    if ($iterator->hasChildren()) {
        // print all children
        foreach ($iterator->getChildren() as $key => $value) {
            echo $key . ' : ' . $value . "\n";
        }
    } else {
        echo "No children.\n";
    }

    $iterator->next();
}
?>

以上例程会输出：

No children.
No children.
a : apple
p : pear

参见

User Contributed Notes

Dominik 23-Jan-2015 11:20
hasChildren() works as documented here, but not as its name suggests.

The method does not return whether the current entry actually *has* children. It only returns whether the element's type is one that is able to have children.

This is a bit counterintuitive if you are processing empty arrays.

Example:

<?php
$data = array(
    "element one" => array(true),
    "element two" => array(),
    "element three" => array(true),
);

$i = new RecursiveIteratorIterator(new RecursiveArrayIterator($data),RecursiveIteratorIterator::SELF_FIRST);

foreach($i as $key => $value)
{
    $type = gettype($value);
    $depth = $i->getDepth();

    if($i->hasChildren()) {
        echo "$depth: $key ($type) has children\n";
    } else {
        echo "$depth: $key ($type) has no children\n";
    }
}
?>

Result:

0: element one (array) has children
1: 0 (boolean) has no children
0: element two (array) has children
0: element three (array) has children
1: 0 (boolean) has no children