關於 php 數組引用的問題

來源:互聯網
上載者:User
php$a =  array(1); $b =& $a[0];   //注釋這條語句最後輸出2,1$c = $a;$c[0]++;echo $c[0].$a[0]; // 輸出 2,2   注釋第二條語句,輸出 2,1 。

回複內容:

php$a =  array(1); $b =& $a[0];   //注釋這條語句最後輸出2,1$c = $a;$c[0]++;echo $c[0].$a[0]; // 輸出 2,2   注釋第二條語句,輸出 2,1 。

http://php.net/manual/en/language.references.whatdo.php

Note, however, that references inside arrays are potentially dangerous. Doing a normal (not by reference) assignment with a reference on the right side does not turn the left side into a reference, but references inside arrays are preserved in these normal assignments. This also applies to function calls where the array is passed by value.

在賦值數組的時候,如果=右邊的資料存在引用,那邊賦值的新數組對應的元素也是引用,所以改變$c[0]的值 也會同時改變$a[0]的值。

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