When a function with arguments is called, the values for the arguments are passed. If they are omitted, you get an error. So to avoid this issue, you can give function arguments a default value that is used if you don't supplie a value.
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="EN" lang="EN">
<head>
<title>PHP</title>
<meta Name="Author" Content="Hann So">
</head>
<body>
<p>
<?php
function Add($num1, $num2 = "3")
{
echo "$num1 + $num2 = ", $num1+$num2, "<br />";
}
Add();
Add(2);
Add(2, 5);
?>
</p>
</body>
</html>
|