Techniques for Working with Return in PHP

There are some techniques for working with return that simplify the code.

Consider, for example, the following code:

<?php
	function func($num) {
		if ($num >= 0) {
			$res = sqrt($num);
		} else {
			$res = 0;
		}
		
		return $res;
	}
	
	echo func(3);
?>

As you can see, in this code, depending on the condition, either one or another value will be assigned to the variable $res. And the last line of the function returns the contents of this variable via return.

Let's rewrite this code in a more shortened form, getting rid of the unnecessary variable $res:

<?php
	function func($num) {
		if ($num >= 0) {
			return sqrt($num);
		} else {
			return 0;
		}
	}
	
	echo func(3);
?>

Given the following function:

<?php
	function func($num1, $num2) {
		if ($num1 > 0 and $num2 > 0) {
			$res = $num1 * $num2;
		} else {
			$res = $num1 - $num2;
		}
		
		return $res;
	}
	
	echo func(3, 4);
?>

Rewrite it in a shortened form according to the studied theory.