©TCP-tryPHP

<!DOCTYPE html>
<html lang="ko">

<head>
	<meta charset="UTF-8">
	<title>PHP Function</title>
</head>

<body>

<?php
function sum($value1, $value2 = 0, $value3 = 0)
{
	return $value1 + $value2 + $value3;
}
	
echo sum(1, 2, 3)."<br>";
echo sum(1, 2)."<br>";
echo sum(1);
//echo sum(); 	// 오류가 발생함.
?>

</body>

</html>