A detailed introduction to the scope in php based on the code

The following is the scope in PHP that I have compiled for you. Interested students can take a look.

The scope of variables

Local scope: Inside a function:

Super Global scope: refers to all code scope
Global scope: is the scope that is not inside the function--outside the function
Note: The local scope cannot access the global scope
If you want to use global variables locally

<?php
$v1 = 1;
  function f1()
  {
     
echo
 "<br /> v1 = $v1";  // 未定义的v1;
 // 若要局部访问全局
 /*
    global $v1; // 声明外部变量的局部变量,此时就可以使用全局变量v1了
 
 */
  }
?>

At this time we can use $GLOBAL['v1'] to access
$GLOBAL is a collection of global variables Super global variables.
If we $ When a certain unit of GLOBAL is unset, it will be completely deleteThe variable
We can also assign values ​​to variables through $GLOBAL
unset($GLOBALS['v6']);

The above is what I compiled for everyone. I hope it will be helpful to everyone in the future.

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