The bool data type represents logical values. It can store only one of two possible values: true or false. Boolean values are commonly used to represent the result of comparisons and control program flow.

This example demonstrates how to declare and display a Boolean variable.

Source Code #

#include <iostream>

int main()
{
    bool is_logged_in = true;

    std::cout << "User Logged In: " << is_logged_in << '\n';

    return 0;
}

Output #

User Logged In: 1

Explanation #

• bool is_logged_in = true; declares a Boolean variable and initializes it with the value true.
• A bool object can store only true or false.
• By default, std::cout prints Boolean values as integers, where true is displayed as 1 and false as 0.
• The manipulators std::boolalpha and std::noboolalpha can be used to display Boolean values as the words true and false instead of 1 and 0.
• std::cout << "User Logged In: " << is_logged_in << '\n'; prints the value stored in the Boolean variable.
• return 0; terminates the program successfully.