Content · Programming · PHP

is_integer

Learn how to use is_integer in PHP with three focused code examples, practical considerations and common mistakes.

2 views Published Oct 16, 2026 Updated Oct 16, 2026

When working with PHP, is_integer can help with a specific task: alias of is_int() with identical behavior.

This guide shows what is_integer does, how to use it in code, and which details you should check before relying on the result.

What Is is_integer in PHP?

Alias of is_int() with identical behavior.

Usage: The following examples show calls with suitable values. Consult the function parameters described in the examples, especially when optional arguments or extensions are involved.

Example 1: Basic Usage

The first example introduces is_integer with a direct PHP expression.

<?php

var_dump(is_integer(12));

Observe the value returned or printed by is_integer and compare it with the input used in this example.

Example 2: A Different Input or Option

This second example demonstrates another input or condition, so you can compare the behavior with the first example.

<?php

var_dump(is_integer(12.0));

Observe the value returned or printed by is_integer and compare it with the input used in this example.

Practical Example

Here is a small scenario illustrating how is_integer can fit into application code. Run the example only in an appropriate development environment if it reads files, changes data, starts processes or connects to a service.

<?php

$value = 27; echo is_integer($value) ? "Integer" : "Not an integer";

Observe the value returned or printed by is_integer and compare it with the input used in this example.

Important Behavior and Edge Cases

  • Core behavior: Alias of is_int() with identical behavior.
  • Important limitation: This is not a different integer type; prefer is_int() for clarity.
  • Production use: Check return values and handle failures before acting on the result.

Comparison With Related Functions

Function or ApproachDifference
is_integer()Alias of is_int() with identical behavior.
is_int()Related approach. Its purpose and return value differ; select it when your task matches that operation.

Common Beginner Mistakes

MistakeCorrect Approach
Overlooking a special case of is_integer().This is not a different integer type; prefer is_int() for clarity.
Using is_integer() without checking the outcome.Handle failures and confirm that the output is suitable for the next step.

Key Takeaways

  • Alias of is_int() with identical behavior.
  • This is not a different integer type; prefer is_int() for clarity.
  • Test the function with relevant inputs before using it in production.

Use is_integer when its behavior matches the job you need to complete. For dependable results, consider the input data, returned value and limitations shown above.

Share this resourceSend this page to someone who may find it useful.