PHP Snippets: Data Types

This post is part of the PHP Snippets series where I will be covering the basics of developing in PHP.

PHP supports a number of data types which are used to store different kinds of values; understanding data types is important as they affect how values are stored, compared, and manipulated.

The main scalar data types in PHP are:

String — a sequence of characters, enclosed in single or double quotes:

$fruit = 'apples';

Integer — a whole number, positive or negative, without a decimal point:

$count = 42;
$temperature = -5;

Float — a number with a decimal point, also referred to as a double:

$price = 9.99;

Boolean — a value that is either true or false, commonly used in conditional logic:

$inStock = true;
$isExpired = false;

In addition to scalar types, PHP also supports the following:

Null — a variable with no value assigned, or one explicitly set to null:

$value = null;

Array — a variable that holds multiple values (covered in more detail in a later post in this series).

Object — an instance of a class, used in object-oriented programming.

You can check the data type of any variable using the gettype() function, or use var_dump() to output both the type and the value together:

$price = 9.99;
echo gettype($price);   // outputs: double
var_dump($price);       // outputs: float(9.99)