What is the use of include_once in php

The function of the include_once statement in php is to include and run the specified file during script execution. The include_once statement is similar to the include statement. The only difference is that the include_once statement does not include the file repeatedly, but only once.

Function: The

include_once statement includes and runs the specified file during script execution.

It is similar to the include statement, the only difference is that if the file has already been included, it will not be included again.

include_once can be used when the same file may be included more than once during script execution, and you want to ensure that it is only included once to avoid problems such as function redefinition and variable reassignment.

Example:

<?php
include_once "a.php"; // 这将包含 a.php文件
?>

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