PHP/String/strval

Checking for an integer

 
if ($_POST["age"] != strval(intval($_POST["age"])) {
    $errors[] = "Please enter a valid age.";
}

Validating an integer with typecasting

 
<?php
if ($_POST["rating"] != strval(intval($_POST["rating"]))) {
   print "Your rating must be an integer.";
}
?>