php中的動態變數的一個應用

流火行者發表於2018-10-29
PHP變數

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

某些情況下，可以代替switch語句，大大簡化程式碼，非常有意思哦

 1 $list = [
 2     [
 3         'type'=>'a',
 4         'name'=>'jimmy0',
 5         'sex'=>'mail'
 6     ],
 7     [
 8         'type'=>'b',
 9         'name'=>'jimmy1',
10         'sex'=>'femail'
11     ],
12     [
13         'type'=>'c',
14         'name'=>'jimmy2',
15         'sex'=>'mail'
16     ],
17     [
18         'type'=>'a',
19         'name'=>'jimmy3',
20         'sex'=>'femail'
21     ],
22     [
23         'type'=>'b',
24         'name'=>'jimmy4',
25         'sex'=>'femail'
26     ],
27     [
28         'type'=>'a',
29         'name'=>'jimmy5',
30         'sex'=>'femail'
31     ]
32 ];
33 $aList = [];
34 $bList = [];
35 $cList = [];
36 foreach ($list as $item) {
37     $v = $item['type'].'List';
38     $$v = array_merge($$v,[$item]);//一般的做法就是在這裡用switch語句了，這邊就不需要了，一行程式碼搞定
39 }
40 var_export($aList);
41 echo PHP_EOL;echo PHP_EOL;
42 var_export($bList);
43 echo PHP_EOL;echo PHP_EOL;
44 var_export($cList);
45 echo PHP_EOL;echo PHP_EOL;
46 exit;

看一下輸出：

 1 array (
 2   0 => 
 3   array (
 4     'type' => 'a',
 5     'name' => 'jimmy0',
 6     'sex' => 'mail',
 7   ),
 8   1 => 
 9   array (
10     'type' => 'a',
11     'name' => 'jimmy3',
12     'sex' => 'femail',
13   ),
14   2 => 
15   array (
16     'type' => 'a',
17     'name' => 'jimmy5',
18     'sex' => 'femail',
19   ),
20 )
21 
22 array (
23   0 => 
24   array (
25     'type' => 'b',
26     'name' => 'jimmy1',
27     'sex' => 'femail',
28   ),
29   1 => 
30   array (
31     'type' => 'b',
32     'name' => 'jimmy4',
33     'sex' => 'femail',
34   ),
35 )
36 
37 array (
38   0 => 
39   array (
40     'type' => 'c',
41     'name' => 'jimmy2',
42     'sex' => 'mail',
43   ),
44 )
45 
46 
47 Process finished with exit code 0
輸出

 

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