将字符串数组转换为 key/values 数组

Question

如何将具有以下结构的多个字符串数组转换为具有php的键值结构？

$mystring = 'first_group, second_group, third_group';

需要像下面这样的数组：

Array ( 
    [0] => Array (
        [key] => first_group 
    ) 
    [1] => Array (
        [key] => second_group 
    ) 
    [2] => Array (
        [key] => third_group 
    )
)

Answer 1

可以用简单的 explode() 和 foreach(),

<?php
$mystring = 'first_group, second_group, third_group';
$results = explode(', ', $mystring);
foreach($results as $row){
    $expected[] = ['key'=>$row];
}
print_r($expected);
?>

演示： https://3v4l.org/FgndX

Answer 2

$result = array_map(
    function($v) { return ['key' => trim($v)]; }, 
    explode(',', 'first_group, second_group, third_group')
);
print_r($result);

Fiddle