Question

我正在尝试使用ID和数据创建一组用户。通常，数据是从数据库接收的，但这里是硬编码的。我正在尝试让users数组返回一个带有id和数据数组的关联数组。由于某种原因，使用'data'访问的数组没有元素，而不是每个包含5和6。

$users = array();
$users[] = array( "id" => 1, "data" => array() );
$users[] = array( "id" => 2, "data" => array() );
foreach( $users as $user_row ) {
    $user_row['data'] [] = 5;
    $user_row['data'] [] = 6;
}

如何在数据中添加内部数组？

Answer 1

将循环更改为

foreach( $users as &$user_row ) {
                   ^---

将$user_row作为引用创建回原始数组元素，或

foreach( $users as $key => $user_row) {
       $users[$key]['data'][] = 5;
       ...
}

Answer 2

foreach循环正在创建子数组的副本，因此循环内部所做的更改不会持久存在。添加＆符号以使$user_row引用原件而不是复制：

foreach( $users as &$user_row )

Answer 3

$users = array();
$users[] = array( "id" => 1, "data" => array() );
$users[] = array( "id" => 2, "data" => array() );
foreach( $users as $key => $user_row ) {
    $users[$key]['data'] [] = 5;
    $users[$key]['data'] [] = 6;
}

Answer 4

不幸的是你的PHP副本版本而不是引用$user_row 尝试

foreach( $users as &$user_row ) {
    $user_row['data'] [] = 5;
    $user_row['data'] [] = 6;
}

Answer 5

foreach对数组的副本进行操作，在其中添加元素将不会执行任何操作。请改用：for ($i = 0; $i < count($users); $i++) {...}

PHP数组语法

5 个答案: