RecursiveArrayIterator::hasChildren

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

RecursiveArrayIterator::hasChildrenReturns 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