Logical Operators in C

Table of Contents

1. Introduction


2. Logical AND Operator (&&)


3. Logical OR Operator (||)


4. Logical NOT Operator (!)


5. Combining Logical Operators


6. Examples and Programs




• Example 1: Using Logical AND Operator


• Example 2: Using Logical OR Operator


• Example 3: Using Logical NOT Operator


• Example 4: Combining Logical Operators




7. Summary

Introduction

In C programming, logical operators are used to perform logical operations on boolean expressions. They allow you to combine multiple conditions and check if they are true or false. C provides three main logical operators: && (logical AND), || (logical OR), and ! (logical NOT). In this post, we will explore each of these operators and understand their functionality with detailed examples.

Logical AND Operator (&&)

The logical AND operator (&&) returns true (1) if both operands are true, otherwise, it returns false (0). It is typically used to combine two or more conditions, and the result is true only if all conditions are true.

Operand 1	Operand 2	Result
true	true	true
true	false	false
false	true	false
false	false	false

Logical OR Operator (||)

The logical OR operator (||) returns true (1) if at least one of the operands is true, otherwise, it returns false (0). It is used to check if any of the conditions are true.

Operand 1	Operand 2	Result
true	true	true
true	false	true
false	true	true
false	false	false

Logical NOT Operator (!)

The logical NOT operator (!) is a unary operator that reverses the logical state of its operand. If the operand is true, the result is false, and vice versa. It is used to negate a condition.

Operand	Result
true	false
false	true

Combining Logical Operators

You can combine multiple logical operators in C to create complex boolean expressions. Parentheses are used to specify the order of evaluation.

Examples and Programs

Example 1: Using Logical AND Operator

#include <stdio.h>

int main() {
    int num1 = 10;
    int num2 = 5;

    if (num1 > 0 && num2 > 0) {
        printf("Both numbers are positive.\n");
    } else {
        printf("At least one number is not positive.\n");
    }

    return 0;
}

Example 2: Using Logical OR Operator

#include <stdio.h>

int main() {
    int num1 = 10;
    int num2 = -5;

    if (num1 > 0 || num2 > 0) {
        printf("At least one number is positive.\n");
    } else {
        printf("Both numbers are not positive.\n");
    }

    return 0;
}

Example 3: Using Logical NOT Operator

#include <stdio.h>

int main() {
    int num = 5;

    if (!(num > 0)) {
        printf("The number is not positive.\n");
    } else {
        printf("The number is positive.\n");
    }

    return 0;
}

Example 4: Combining Logical Operators

#include <stdio.h>

int main() {
    int num = 10;

    if (num > 0 && num % 2 == 0) {
        printf("The number is positive and even.\n");
    } else if (num > 0 && num % 2 != 0) {
        printf("The number is positive and odd.\n");
    } else {
        printf("The number is either zero or negative.\n");
    }

    return 0;
}

Summary

Logical operators (&&, ||, and !) are essential in C programming to work with boolean expressions. They allow you to evaluate multiple conditions and make decisions based on their truth values. Understanding these operators will help you write more efficient and effective C programs.

In conclusion, logical operators play a vital role in controlling program flow and making decisions based on multiple conditions. They are essential tools in a C programmer's toolkit, enabling the creation of complex decision-making structures. By mastering these operators, you can write more efficient and robust C programs. Happy coding!