call by value, reference

1. call by value

 

<?php	//함수 입력부분 call by value
	function swap($a,$b) {
		$temp = $a;
		$a = $b;
		$b = $temp;
	}

	$i=3;
	$j=4;

	print "Before : $i, $j 
";
	swap($i, $j);
	print "After : $i, $j 
";
?>

 

 

2. call by reference

<?php 	//함수 입력부분 call by reference
	
	function swap(&$a, &$b) {
		$temp = $a;
		$a = $b;
		$b = temp;
	}

	$i=3;
	$j=4;

	print "Before : $i, $j 
";
	swap($i, $j);
	print "After : $i, $j 
";
?>