Using PHP is_int() Function to Check Integer Variables

PHP provides the built‑in is_int() function to determine whether a variable is of integer type, returning true for integers and false otherwise.

The function signature is bool is_int ( mixed $var ), where $var can be any type.

Example 1 defines three variables—a integer, a float, and a string—and uses var_dump(is_int(...)) to show the function returns true only for the integer.

<?php
$num1 = 10; // integer
$num2 = 10.5; // float
$str = "10"; // string

var_dump(is_int($num1)); // bool(true)
var_dump(is_int($num2)); // bool(false)
var_dump(is_int($str)); // bool(false)
?>

Example 2 creates three variables of different types and uses if (is_int(...)) { echo "..."; } else { echo "..."; } to output messages indicating whether each variable is an integer.

<?php
$var1 = 123;
$var2 = "abc";
$var3 = true;

if (is_int($var1)) {
    echo "Variable 1 is an integer";
} else {
    echo "Variable 1 is not an integer";
}

if (is_int($var2)) {
    echo "Variable 2 is an integer";
} else {
    echo "Variable 2 is not an integer";
}

if (is_int($var3)) {
    echo "Variable 3 is an integer";
} else {
    echo "Variable 3 is not an integer";
}
?>

In summary, is_int() is a useful PHP function for quickly checking variable types, helping developers handle data appropriately in backend applications.