sum of 2 var in php code example

Example 1: addition in php

<?php  
$x=15;  
$y=30;  
$z=$x+$y;  
echo "Sum: ",$z;  
?>

Example 2: add two numbers as string in php

$num = "3.14";
$int = (int)$num;
$float = (float)$num;