PHP Development Variables (ii)

Let's take a piece of this article to learn the scope of the variable. Variables must conform to the defined rules of a variable when used, and variables must be used within a valid range, beyond the valid range, where the variable is meant to be.

The scope of the variable is the following table:

Let's run a piece of code to distinguish between global variables and variables within functions, with the following code:

<?php$jackstr = "I am a global variable";  Define global variables function output () {$jackStr = "I am a variable within a function";  Defines the variable inside the function echo $jackStr; echo "\ n";} Output ();     The variable echo $jackStr in the output function;   Output global variable?>

The output results are as follows:

Let's look at the method of using global variable values within a function, with the following code:

<?php$leestr = "I am a global variable * * *";  Define global variables function output () {$jackStr = "I am a variable within a function * * *";  Defines the variable in the function echo $jackStr; echo "\ n"; global $leeStr; echo $leeStr;} Output ();     Calling function Output variable?>

The results of the operation are as follows:

PHP Development Variables (ii)