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The difference between passing by value and passing by reference in php
The difference between passing by value and passing by reference in php
This article mainly introduces the difference between passing values and passing references in calling PHP. It has certain reference value. Now I share it with everyone. Friends in need can refer to it
#Daniel’s explanation:
Passing value : Same as copy. [For example, I have a house. I give you building materials. You build a house that is exactly the same as mine. Whatever you do in your house will not affect me. I will do it in mine. Whatever happens in the house will not affect you, they are independent of each other. 】
view plain copy
<?php $testa=1; //定义变量a $testb=2; //定义变量b $testb = $testa; //变量a赋值给变量b echo $testb; //显示为1 ?>
Pass reference : Similar to pointers in C language, it feels almost the same. For example, I have a house. If I give you a key, both of us can enter the house. Whatever you do in the house will affect me.
copy
<?php $param2=1; //定义变量2 $param1 = &$param2; //将变量2的引用传给变量1 echo $param2; //显示为1 $param1 = 2; //把2赋值给变量1 echo $param2; //显示为2 ?>
- ##[Advantages and Disadvantages:] Passing values will be time-consuming. Especially for large strings and objects, this will be a very expensive operation. Transferring references. Any operation within the function is equivalent to the operation of transferring variables. Transferring large variables is efficient!
##Please indicate the source for reprinting https://blog.csdn.net/qq_28194557/article/details/70543753
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