PHP: Simple Reference Example

/************************
Example 1
************************/
$a = 1;
$b = $a;
$b = 2;
 
echo "a:{$a} / b: {$b}" . "<br />";
 
//$b is now going to become a reference to $a or in other words, an alias
$a = 1;
$b =& $a;
$b = 2;
 
echo "a:{$a} / b: {$b}" . "<br />";
 
//Unset the $b reference (or alias)
unset($b);
 
//$b will not be set to nothing
echo "a:{$a} / b: {$b}";
 
echo "<hr />";
 
/************************
Example 2: Using References as Function Arguments
************************/
 
//Version 1
function example1(){
	global $a;
	$a = $a + 1;
}
$a = 10;
example1( $a );
echo $a . "<br />";
 
//Version 2
function example2( &$var ){
//When something comes in, don't take its value, make a reference of it's value
	$var = $var + 1;
}
 
$a = 10;
example2( $a );
echo $a . "<br />";