is_numeric in action

<?php
   $item = 43;
   echo "The variable \$item is numeric: ".is_numeric($item)."<br />";
?>

1.	PHP Data Types
2.	gettype() and settype() Data Types
3.	Returns true if $a is an array
4.	Returns true if $a is a floating-point number
5.	Returns true if $a is an integer
6.	Create Object and check its type
7.	Create Object and get its type
8.	Returns true if $a is a string

is_numeric in action : Data Type « Data Type « PHP