Checking for a whole number in php

There may be a simpler way but I didn’t come across one except this handy function when dealing with decimal numbers.

////////////////////////////////////////////////////////////////////////////////////////////// 
//is_wholeNumber(string $value)
//Returns TRUE if a WHOLE NUMBER
//Returns FALSE if anything else (Float, String, Hex, etc)
//////////////////////////////////////////////////////////////////////////////////////////////   
function is_wholeNumber($value)
{
	if(preg_match ("/[^0-9]/", $value))
	{	return FALSE;	}
	return TRUE;
}

There is also ctype_digit but this seems to return false when using addition like so:

$numeric_string = '1'+'1';
$integer = 1+1;

if(ctype_digit($numeric_string)) { echo "true";} else { echo "false"; }  // false
if(ctype_digit($integer)){ echo "true";} else { echo "false"; }          // false 

if(is_numeric($numeric_string)){ echo "true";} else { echo "false"; }    // true
if(is_numeric($integer)){ echo "true";} else { echo "false"; }           // true

Both equal 2 yet ctype_digit returns false? , is_numeric works here but as i’m dealing with decimal places this returns true when it is not a whole number.

Credit for the function due to http://davidwalsh.name/php-validatie-numeric-digits