C Booleans

Booleans

Very often, in programming, you will need a data type that can only have one of two values, like:

• YES / NO

• ON / OFF

• TRUE / FALSE

For this, C has a bool data type, which is known as booleans.

Booleans represent values that are either true or false.

Boolean Variables

In C, the bool type is not a built-in data type, like int or char.

It was introduced in C99, and you must import the following header file to use it:

A boolean variable is declared with the bool keyword and can only take the values true or false:

Before trying to print the boolean variables, you should know that boolean values are returned as integers:

• 1 (or any other number that is not 0) represents true

• 0 represents false

Therefore, you must use the %d format specifier to print a boolean value:

However, it is more common to return a boolean value by comparing values and variables.

Comparing Values and Variables

Comparing values are useful in programming, because it helps us to find answers and make decisions.

For example, you can use a comparison operator, such as the greater than (>) operator, to compare two values:

From the example above, you can see that the return value is a boolean value (1).

You can also compare two variables:

In the example below, we use the equal to (==) operator to compare different values:

You are not limited to only compare numbers. You can also compare boolean variables, or even special structures, like arrays 

Remember to include the <stdbool.h> header file when working with bool variables.