Logical and Comparison Operators

Logical and comparison operators help in evaluating conditions in C.

In this lesson, you will learn about:

• Comparison operators like ==, !=, >, and <.
• Logical operators like &&, ||, and !.

Comparison Operators

Comparison operators are used to compare two values.

Examples:

• == (Equal to)
• != (Not equal to)
• > (Greater than)
• < (Less than)

Example: Comparison Operators

This program demonstrates comparison operators.

#include <stdio.h>

int main() {
    int a = 5, b = 10;
    printf("a == b: %d\n", a == b);
    printf("a != b: %d\n", a != b);
    printf("a > b: %d\n", a > b);
    printf("a < b: %d\n", a < b);
    return 0;
}

Logical Operators

Logical operators are used to combine multiple conditions.

Examples:

• && (Logical AND)
• || (Logical OR)
• ! (Logical NOT)

Example: Logical Operators

This program demonstrates logical operators.

#include <stdio.h>

int main() {
    int x = 5, y = 10;
    printf("(x > 0 && y > 0): %d\n", (x > 0 && y > 0));
    printf("(x > 0 || y < 0): %d\n", (x > 0 || y < 0));
    printf("!(x > 0): %d\n", !(x > 0));
    return 0;
}

Using Operators in Conditions

Comparison and logical operators are commonly used in if statements.

Example:

if (age >= 18 && age <= 65) { printf("Eligible for work."); }

Example: Using Operators in if Statements

This program checks if a number is between 1 and 100.

#include <stdio.h>

int main() {
    int num = 50;
    if (num > 0 && num <= 100) {
        printf("Number is in range.\n");
    } else {
        printf("Number is out of range.\n");
    }
    return 0;
}

Common Mistakes

Here are common mistakes when using operators:

• Using = instead of == in comparisons.
• Forgetting parentheses in complex conditions.
• Incorrectly using logical AND (&&) and OR (||).

Summary

In this lesson, you learned:

• Comparison operators: ==, !=, >, <.
• Logical operators: &&, ||, !.
• How to use these operators in conditions.

Next, we will move on to functions and modular programming in C!