The four major scopes of PHP variables

PHP variable scope

● local

● global

● static

● parameter

Local scope, global scope

        

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PHP global keyword

The global keyword is used to access global variables within a function.

To call global variables defined outside the function within a function, you can add the global keyword before the variables in the function.

        

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PHP stores all global variables in an array called $GLOBALS.

So the above code can be written in another way:

        

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PHP Static scope

PHP When a function completes, all its variables are usually will be deleted. In order to prevent some local variables from being deleted, you can use the static keyword when declaring the variable for the first time.

        

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Parameter scope (formal parameter)

Parameter declaration as part of the function declaration.

        

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Small addition:

Print array method:

echo '
'; print_r($arr);
        

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