Question

我需要在它们之间创建嵌套的foreach循环，因为有数组的元素。

示例：

这是从

开始的数组

print_r($container);



Array
(
    [list1] => Array
        (
            [0] => Array
                (
                    [id_topic] => 45
                    [id_topicGroup] => 44
                    [topic] => topic1 di 44
                )

            [1] => Array
                (
                    [id_topic] => 46
                    [id_topicGroup] => 44
                    [topic] => topic2 di 44
                )

            [2] => Array
                (
                    [id_topic] => 47
                    [id_topicGroup] => 44
                    [topic] => topic3 di 44
                )

        )

    [list2] => Array
        (
            [0] => Array
                (
                    [id_topic] => 48
                    [id_topicGroup] => 45
                    [topic] => topic1 di 45
                )

            [1] => Array
                (
                    [id_topic] => 49
                    [id_topicGroup] => 45
                    [topic] => topic2 di 45
                )

            [2] => Array
                (
                    [id_topic] => 50
                    [id_topicGroup] => 45
                    [topic] => topic3 di 45
                )

        )

)

这是打印此案例的元素的处理

foreach($container)['list1'] as $el_lista1) {
                foreach($container)['list2'] as $el_lista2) {
                    echo $el_lista1 . " " . $el_lista2 . "<br>\n";
                }                
            }

这是输出

topic1 di 44 topic1 di 45

topic1 di 44 topic2 di 45

topic1 di 44 topic3 di 45

topic2 di 44 topic1 di 45

topic2 di 44 topic2 di 45

topic2 di 44 topic3 di 45

topic3 di 44 topic1 di 45

topic3 di 44 topic2 di 45

topic3 di 44 topic3 di 45

但问题是它必须像我一样在内部管理无限数量的列表和论坛？

我认为我需要根据这些列表的数量在它们之间创建一些内部foreach循环。你能做这个吗？

Answer 1

您需要使用RecursiveArrayIterator

<?php
$arr=Array
(
    "list1" => Array
        (
            "0" => Array
                (
                    "id_topic" => 45,
                    "id_topicGroup" => 44,
                    "topic" => "topic1 di 44"
                ),

            "1" => Array
                (
                    "id_topic" => 46,
                    "id_topicGroup" => 44,
                    "topic" => "topic2 di 44",
                ),
            "2" => Array
                (
                    "id_topic" => 47,
                    "id_topicGroup" => 44,
                    "topic" => "topic3 di 44",
                )

        ),

    "list2" => Array
        (
            "0" => Array
                (
                    "id_topic" => 48,
                    "id_topicGroup" => 45,
                    "topic" => "topic1 di 45"
                ),

            "1" => Array
                (
                    "id_topic" => 49,
                    "id_topicGroup" => 45,
                    "topic" => "topic2 di 45",
                ),

            "2" => Array
                (
                    "id_topic" => 50,
                    "id_topicGroup" => 45,
                    "topic" => "topic3 di 45"
                )

        )

);

$iterator = new RecursiveArrayIterator($arr); 
iterator_apply($iterator, 'traverseStructure', array($iterator)); 

// from php manual

function traverseStructure($iterator) { 

    while ( $iterator -> valid() ) { 

        if ( $iterator -> hasChildren() ) { 

            traverseStructure($iterator -> getChildren()); 

        } 
        else { 
            echo $iterator -> key() . ' : ' . $iterator -> current() .'<br>';    
        } 

        $iterator -> next(); 
    } 
}

//print according to your need

输出：

id_topic : 45
id_topicGroup : 44
topic : topic1 di 44
id_topic : 46
id_topicGroup : 44
topic : topic2 di 44
id_topic : 47
id_topicGroup : 44
topic : topic3 di 44
id_topic : 48
id_topicGroup : 45
topic : topic1 di 45
id_topic : 49
id_topicGroup : 45
topic : topic2 di 45
id_topic : 50
id_topicGroup : 45
topic : topic3 di 45

在数组的元素上创建嵌套的foreach

1 个答案: