How to Add custom parameters into the body_class() function ?

When creating a website on WordPress, it can be really useful to be able to add one (or more) custom parameter into the body_class() function. Here is a function I use very often when building sites for my clients.

Copy and paste this code in your themes function.php files

function custom_body_class($classes){
	if(is_singular()){
		$myvar = "myparam";
	} else {
		$myvar = "anotherparam";
	}
	global $post;
	array_push($classes, $myvar);
	return $classes;
}
add_filter('body_class', 'custom_body_class');

Save file. Enjoy Code!