Introduction:
This tutorial will cover boolean variables in PHP.

What is a variable?
A variable is a piece of information which holds a value. Each variable has a type and a reference name. The value of a variable will depend on the type for that particular variable.

What types can a variable be?
There are a few different basic types of variable which include;
Strings
Booleans
Integers

Strings hold characters, letters, numbers and symbols in a string format (essentially a character array), Booleans hold a true or false value and Integers hold a full number.

When are booleans used?
Booleans are used to determine if something is true or false and as such it can only hold a 'true' or 'false' value. Booleans are used in statements such as the if and else.

Bool is the shorthand version of Boolean.

Examples:
Creating a boolean variable named 'bool':

1. $bool
   
   ;
   

Creating and initializing a boolean variable named 'bool':

1. $bool
   
   =
   
   true
   
   ;
   

Checking if bool is true, and if it is outputting 'Yes':

1. $bool
   
   =
   
   true
   
   ;
   
2. if
   
   (
   
   $bool
   
   )
   
   {
   
3. echo
   
   'Yes'
   
   ;
   
4. }
   

Checking if bool is true, and if it is outputting 'Yes'; the below code would NOT output:

1. $bool
   
   =
   
   false
   
   ;
   
2. if
   
   (
   
   $bool
   
   )
   
   {
   
3. echo
   
   'Yes'
   
   ;
   
4. }
   

Even though our boolean is not a string, we can still output the value. However; if it is true, it will be a string value of '1'; and a '0' if it is false:

1. $bool
   
   =
   
   true
   
   ;
   
2. echo
   
   $bool
   
   ;
   

Book traversal links for PHP Boolean Variables

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