How to Check a Variable’s Type in PHP

So, you want to know how to determine a variable’s data type in PHP? Read on; this tutorial will show you how!

Published Categorized as PHP

Welcome to today’s PHP tutorial, where we’ll be diving into the world of PHP yet again, and learning how to get the type of a variable.

If you’ve ever found yourself scratching your head and wondering about the kind of data you’re working with in PHP, that’s exactly what we’re going to be covering today. Awesome, let’s get started!

Checking a Variable’s Type

To determine the type of a variable in PHP, we can use the built-in gettype() function. This function takes a single parameter, which is the variable that you want to check, and returns a string representing that variable’s data type.

Here’s an example:

$number = 42;
gettype($number); // integer

In the above example, we have a variable called $number, which contains the value 42. To check its type, we call gettype($number) and it returns the string "integer".

Similarly, if we have a variable $string containing the value "Hello, world!", calling gettype($string) will return "string", like so:

$string = "Hello, world!";
gettype($string); // string

Getting to Know the gettype() Function

There are only so many data types in PHP, which means that the gettype() function will return a limited set of possible types, which include:

  • "boolean" for boolean values (true or false)
  • "integer" for integer values
  • "float" for floating-point values
  • "double" for floating-point values (same as "float")
  • "string" for string values
  • "array" for arrays
  • "object" for objects
  • "resource" for resources
  • "NULL" for null values
  • "unknown type" for any other type of value

Alternative Methods

In addition to gettype(), PHP also provides the is_* family of functions that allow us to check whether a variable is of a certain type.

For example, is_int($number) will return true if $number is an integer and false otherwise. Here’s an example:

$number = 42;

if (is_int($number)) {
    echo "The variable's data type is an integer.";
} else {
    echo "The variable's data type is not an integer.";

This function is helpful when you need to verify if a given variable is of a certain data type.

By Dim Nikov

Editor of Maker's Aid. Part programmer, part marketer. Making things on the web and helping others do the same since the 2000s. Yes, I had Friendster and Myspace.

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