Chapter 7. Types

Table of Contents
Introduction
Booleans
Integers
Floating point numbers
Strings
Arrays
Objects
Resource
NULL
Type Juggling

Introduction

PHP supports eight primitive types.

Four scalar types:

Two compound types:

And finally two special types:

Note: In this manual you'll often find mixed parameters. This pseudo-type indicates multiple possibilities for that parameter.

The type of a variable is usually not set by the programmer; rather, it is decided at runtime by PHP depending on the context in which that variable is used.

Note: If you want to check out the type and value of a certain expression, use var_dump().

If you simply want a human-readable representation of the type for debugging, use gettype(). To check for a certain type, do not use gettype(), but use the is_type functions.

If you would like to force a variable to be converted to a certain type, you may either cast the variable or use the settype() function on it.

Note that a variable may behave in different manners in certain situations, depending on what type it is at the time. For more information, see the section on Type Juggling.