How to use Variable scope in PHP?

[super soaker]

Hello friends,
I am new to the PHP programming language. So I don't know much about it. I just went through the term variable scope. Before that I have done Core Java and C++ programming language, so I can guess what can it means but I am not sure about it. Please can anyone tell me how to use Variable scope in PHP? Help me as soon as possible.

[Allan.d]

In PHP there is something called scope, which relates to variables. The scope of a variable is the context within which it is defined. The scope is the area in which the variable is declared. You set your scope with curly braces (the { and } characters) in PHP. You should also know the basic thing that functions keep their own sets of variables that are distinct from those of the page and of other functions. The variables defined in a function, including its parameters, are not accessible outside the function.

[Warner]

In PHP, mostly all the part has only a single scope. Variables defined outside a function are not accessible inside the function by default. The single scope spans included and required files as well :

$a = 4;

function call( ) {
  $a += 3;
}

call( );
echo $a; 

[MELTRONICS]

Any variable that you are using inside a function is by default limited to the local function scope. You can check the following example :

<?php
$a = 3; 

function test()
{ 
    echo $3; 
} 

test();
?>

[CodGuru]

You can use the global for the variable scope in PHP, like I have done in following code :

<?php
$a = 3;
$b = 5;

function Sum()
{
    global $a, $b;

    $b = $a + $b;
} 

Sum();
echo $b;
?>