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This article summarizes the scope of several situations when including files in PHP. It is very simple and practical. I hope it will be helpful for everyone to become familiar with the use of include.
In php we sometimes need to include a file. For example, when I was writing a framework some time ago, I planned to use native PHP as the template, and then write a display method to introduce the template file, but this was just my imagination.
After finishing writing, I found that all variables in the template were undefined. Through various research and searching for information, I summarized the scope in several situations when including files.
The first situation: A file includes B file, and the variables in A can be called in B file.
A file code:
<?php $aaa = '123'; include "B.php";
<?php echo $aaa;
Second case: A file includes B file, and then the variables of B file can be called in A file. A file code:
<?php include "B.php"; echo $fff;
<?php $fff = 'i am f';
The third situation: Call B file in a method of a certain class in A file, and then the variables in the method can be called in B file. A file code:
<?php class test{ public function show(){ $bbb = 'abc'; include "B.php"; } } $t = new test; $t->show();
<?php echo $bbb;
Fourth case: A file imports B file through a defined function. Variables in A cannot be used in B file, but functions (display) can be called in A file. variables in . A file code:
<?php $aaa = '123'; function display($file){ $bbb= 'asdasdas'; include $file; } display("B.php");
<?php echo $aaa; echo $bbb;
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A brief description of the four functions of php include, include_once, require, require_once
Detailed explanation of how to use php include_once
##Detailed explanation of how to use php include
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