php中的动态变量的一个应用

原文：https://www.cnblogs.com/JimmyBright/p/9869168.html

某些情况下，可以代替switch语句，大大简化代码，非常有意思哦

$list = [
    [
        'type'=>'a',
        'name'=>'jimmy0',
        'sex'=>'mail'
    ],
    [
        'type'=>'b',
        'name'=>'jimmy1',
        'sex'=>'femail'
    ],
    [
        'type'=>'c',
        'name'=>'jimmy2',
        'sex'=>'mail'
    ],
    [
        'type'=>'a',
        'name'=>'jimmy3',
        'sex'=>'femail'
    ],
    [
        'type'=>'b',
        'name'=>'jimmy4',
        'sex'=>'femail'
    ],
    [
        'type'=>'a',
        'name'=>'jimmy5',
        'sex'=>'femail'
    ]
];
$aList = [];
$bList = [];
$cList = [];
foreach ($list as $item) {
    $v = $item['type'].'List';
    $$v = array_merge($$v,[$item]);//一般的做法就是在这里用switch语句了，这边就不需要了，一行代码搞定
}
var_export($aList);
echo PHP_EOL;echo PHP_EOL;
var_export($bList);
echo PHP_EOL;echo PHP_EOL;
var_export($cList);
echo PHP_EOL;echo PHP_EOL;
exit;

看一下输出：

array (
  0 => 
  array (
    'type' => 'a',
    'name' => 'jimmy0',
    'sex' => 'mail',
  ),
  1 => 
  array (
    'type' => 'a',
    'name' => 'jimmy3',
    'sex' => 'femail',
  ),
  2 => 
  array (
    'type' => 'a',
    'name' => 'jimmy5',
    'sex' => 'femail',
  ),
)

array (
  0 => 
  array (
    'type' => 'b',
    'name' => 'jimmy1',
    'sex' => 'femail',
  ),
  1 => 
  array (
    'type' => 'b',
    'name' => 'jimmy4',
    'sex' => 'femail',
  ),
)

array (
  0 => 
  array (
    'type' => 'c',
    'name' => 'jimmy2',
    'sex' => 'mail',
  ),
)


Process finished with exit code 0