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Boolean

Part of the Fundamentals section of Coddy's C# journey — lesson 8 of 69.

A boolean type has only 2 possible values: true or false.

To assign a boolean value to a variable, use the keyword bool followed by the variable name:

bool variableTrue = true;
bool variableFalse = false;

In the above example, two boolean variables named variableTrue and variableFalse are initialized with the values true and false, respectively.

Booleans are the building blocks for creating logic in the programs we write.

Challenge

Beginner

Declare a variable named isLoggedIn and assign it the value true.

Cheat sheet

A boolean type has only 2 possible values: true or false.

To declare a boolean variable, use the keyword bool followed by the variable name:

bool variableTrue = true;
bool variableFalse = false;

Try it yourself

using System;

public class Program {
    public static void Main(string[] args) {
        // Type your code below
        bool isLoggedIn = ?
        
        // Don't change the line below
        Console.WriteLine("isLoggedIn = " + isLoggedIn);
    }
}

Test yourself

This lesson includes a short quiz. Start the lesson to answer it and track your progress.

All lessons in Fundamentals

1Introduction

C#Hello World!Comments Basic Program Structure

4Operators Part 1

Arithmetic Operators Modulo Operator Increment/Decrement Post Increment/Decrement Arithmetic Shortcuts

7Basic IO

Basic Output String Interpolation Reading Input Parse Recap - Till 120 Recap - True or False

10Methods (Functions)

Declaring Methods Method Parameters Return Types Optional Parameters Recap - Validation Function Void Methods

13Iterating Over Collections

Using For Loop Foreach Loop Common Array Operations

2Variables Part 1

Numbers Char StringBooleanType Declaration

5Operators Part 2

Comparison Operators Logical Operators Part 1 Logical Operators Part 2 Recap - Simple Logic Logical Operators Part 3

8Calculator App

Welcome Message Getting Numbers

Project lesson

Basic Operations

Project lesson

Formatted Output

Project lesson

11Arrays Basics

Declaring Arrays Accessing Elements Modifying Arrays Array Methods Recap - Product Array Edit Recap - Reversed Array

14Final Challenges

Number Pattern Pattern Finder Student Grade Calculator

3Variables Part 2

Var Constants Naming Conventions Recap - Initialize Variables Type Casting

6Decision Making

If Statement If - Else Switch Statement Ternary Operator Recap - If Else Nested If - Else

9Loops

For Loop While Loop Do While Loop Break Continue Nested Loop Infinite Loop Recap - Dynamic Input

12String Operations

String Methods Part 1 String Methods Part 2 String Formatting