php底层变量分析 

 1 <?php
 2 
 3 
 4 //数组引用
 5 $arr = array('a','b','c','d');
 6 $x = & $arr[1];
 7 $tmp = $arr;
 8 $arr[1] = 'e';
 9 echo $tmp[1];  //e
10 
11 //数组指针
12 $arr = array('a','b','c','d');
13 foreach($arr as $key => $val){
14 }
15 var_dump(current($arr));  //boolean false
16 
17 foreach($arr as $key => $val){
18     $arr[$key]=$val;
19 }
20 var_dump(current($arr)); //b
21 
22 
23 
24 /*Array
25 (
26     [0] => a
27     [1] => b
28     [2] => c
29     [3] => a
30 )
31 Array
32 (
33     [0] => a
34     [1] => b
35     [2] => c
36     [3] => b
37 )
38 Array
39 (
40     [0] => a
41     [1] => b
42     [2] => c
43     [3] => c
44 )
45 Array
46 (
47     [0] => a
48     [1] => b
49     [2] => c
50     [3] => c
51 )*/
52 foreach($arr as &$v){
53 }
54 
55 foreach($arr as $v){
56     print_r($arr);
57 }

 

posted @ 2015-04-29 09:14  lpfuture  阅读(187)  评论(0)    收藏  举报