How to check if a variable is an Integer in PHP?
Which methods are available in PHP to check if a variable is an Integer? In this tutorial, we are going to see how to check if a variable is an Integer in PHP.
is_int()
The function is_int($var) returns whether the passed variable is an Integer or not:
<?php
var_dump( is_int(1) ); // true
var_dump( is_int(0) ); // true
var_dump( is_int(-1) ); // true
var_dump( is_int(1.0) ); // false
var_dump( is_int('1') ); // false
var_dump( is_int(true) ); // false
var_dump( is_int(new stdClass()) ); // false
?>
Output:
bool(true) bool(true) bool(true) bool(false) bool(false) bool(false) bool(false)
Test for Integer parameters
It makes sense to use is_int() to check function parameters:
<?php
function square($val)
{
if (!is_int($val))
{
echo("The number passed is not an integer.\n");
}
else
{
echo("Square of $val: ".($val * $val)."\n");
}
}
square(2);
square(0.4);
square("StackHowTo");
square(true);
?>
Output:
Square of 2: 4 The number passed is not an integer. The number passed is not an integer. The number passed is not an integer.





