Logical Operators Part 1

Part of the Fundamentals section of Coddy's C journey — lesson 21 of 63.

Logical operators are used to check combinations of comparisons that return 1 (true) or 0 (false).

For example, the following statement contains two comparisons:

Is 5 greater than 3 and less than 6?

Operator	Meaning	Example
`&&`	And - `1` if all operands are `1`	`a && b`
`\|\|`	Or - `1` if any operand is `1`	`a \|\| b`
`!`	Not - `1` if the operand is `0`	`!a`

Let's see some examples:

5 is greater than 3 and 1 equals 1:

int b1 = (5 > 3) && (1 == 1); // holds 1 (true)

Explanation: All of the operands are 1, so b1 will hold 1 (and operation is 1 if both operands are 1) .

5 is not equal to 4 or 5 equals 2:

int b2 = !(5 == 4) || (5 == 2); // holds 1 (true)

Explanation: The first operand (5 != 4) is 1 so b2 is also 1 (or operation is 1 if either one of the operands is 1)

Challenge

Easy

You are given code. Replace the question marks of the variables int b1 and int b2 so that int b3 holds 1 (true).

Take a moment to analyze the condition and think about what values would make it true.

There are many right solutions!

Try it yourself

#include <stdio.h>

int main() {
    // Type your code below
    int b1 = ?;
    int b2 = ?;
    int b3 = b1 || b2;
    
    // Don't change the line below
    printf("b3 = %d", b3);
    return 0;
}

Test yourself

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

All lessons in Fundamentals

1Introduction

C Language Hello World!Comments Basic Program Structure

4Control Flow

If Statement If - Else Else-If Switch Case Ternary Conditional Operator Recap Challenge Nested If - Else

7Functions

Declare a Function Return Types Parameters Recap Challenge #1 Recursion Basics Function Prototypes Recap Challenge #2

3Operators

Arithmetic Operators Modulo Operator Increment/Decrement Assignment Operators Relational OperatorsLogical Operators Part 1Logical Operators Part 2 Logical Operators Part 3 Recap Challenge

6Loops

For Loop While Loop Do While Loop Break Continue Recap Challenge #1 Nested Loops Infinite Loops Recap Challenge #2

9Final Challenges

Grades Peaks TV