PHP function variable scope and function return value tutorial

In PHP, variables that are defined in a function, including parameters, cannot access the external variables of the function, and, by default, variables that are defined outside a function cannot be accessed by a variable.

Below is an example of the code below:

<?php

$a = 1;

$b = 2;

function Sum ()

{

Global $a, $b;

$b = $a + $b;

}

Sum ();

Echo $b;

?>

This returns the value of $b to 3, and in PHP, Global is an all-in-one variable, then we now look at the PHP variable reference instance, the code is as follows:

<?php

Function Str_unite (& $string)

{

$string. = ' also like blue. ';

}

$str = ' like red, ';

Str_unite ($STR);

Echo $str; Output: ' Like red, also like blue. '

?>

Above is the function of the scope of the global variables and functions of reference, the following is a function of the local variables, the code is as follows:

<?php

$a = 1;

$b = 2;

function Sum ($a, $b)

{//Open source code phpfensi.com

$b = $a + $b;

echo $b;//3

}

Sum ();//

echo $b;//2

?>

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