Boolean Data Type in PHP

Introduction

In this article I will explain Boolean data types in PHP. Boolean is the simplest type. A Boolean expression is a true type value. It is used in control structures like for testing portions of an if statement. It can be either TRUE or FALSE.

Types of the Boolean Value

Data Type	True Value	False Value
Integer	All the non-zero values	0
Floating Point	All the non-zero values	0.0
Null	Never	Always
Array	If it is contains only one elements	Does not contains any elements
String	All other string	Empty string ()"" The Zero string ()"0"
Object	Always	Never
Resource	Always	Never

Example

<?php 

$height=100; 

$width=50; 

if ($width == 0) 

{ 

echo "The width needs to be a non-zero number"; 

} 

?>

In the above example, it would be false and, therefore, the echo statement will never execute.

<?php

$height=100; 

$width=50; 

if ($width)

{

 echo "The area of the rectangle is  

($height*$width)";

} 

else

{

echo "The width needs to be a non-zero number";

} 

?>

This example does not compare $height and $width. PHP automatically converted the $width value of 50 to Boolean. The calculated area of the rectangle is displayed inside the if() statement.

Output

Converting to Boolean

<?php

var_dump((bool)  "");       

var_dump((bool)  1);        

var_dump((bool)  -2);      

var_dump((bool) "raaa");    

var_dump((bool) 2.3e5);    

var_dump((bool) array(12));

var_dump((bool) array());  

var_dump((bool) "false"); 

?>

Output