C Logical Operators 🎯

Welcome to our deep dive into C Logical Operators! In this lesson, we'll explore how to combine simple conditions to make more complex ones, using the power of logical operators. Let's get started! 📝

What are Logical Operators?

Logical operators allow us to combine multiple conditions in a C program. They help us create more complex and powerful conditions, enabling us to make decisions based on multiple variables or conditions.

There are three logical operators in C:

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

Logical AND (&&) 💡

The && operator checks if both the conditions are true. If both conditions are true, then only the overall condition becomes true.

Example:

#include <stdio.h>

int main() {
    int a = 10, b = 20;

    if (a > 5 && b > 15) {
        printf("Both conditions are true.\n");
    }

    return 0;
}

In this example, we have two conditions: a > 5 and b > 15. If both conditions are true, then the overall condition is true, and the message "Both conditions are true." is printed.

Try modifying the values of a and b to understand how the && operator works!

Logical OR (||) 💡

The || operator checks if at least one of the conditions is true. If at least one condition is true, then the overall condition becomes true.

Example:

#include <stdio.h>

int main() {
    int a = 10, b = 5;

    if (a > 5 || b > 15) {
        printf("At least one condition is true.\n");
    }

    return 0;
}

In this example, we have two conditions: a > 5 and b > 15. Since a > 5 is true, the overall condition is true, and the message "At least one condition is true." is printed.

Modify the values of a and b to see how the || operator behaves.

Logical NOT (!) 💡

The ! operator negates the value of a condition. If the original condition is true, the negated condition is false, and vice versa.

Example:

#include <stdio.h>

int main() {
    int a = 10;

    if (!(a < 5)) {
        printf("a is not less than 5.\n");
    }

    return 0;
}
``

In this example, we have the condition a < 5. By using the ! operator, we negate this condition, meaning the overall condition is true if a is not less than 5.

Try changing the value of a to test the ! operator.

Quiz 📝

Practice 🎯

Write a program that uses logical operators to check if a user is eligible to vote. The conditions are as follows:

Age should be greater than or equal to 18.
If the user is a citizen of India, they can vote. If not, they can vote only if they have a permanent residency in India.

Here is a hint:

#include <stdio.h>

int main() {
    int age = 17;
    char nationality = 'I'; // 'I' for Indian, 'F' for Foreign

    // Complete the code to check if the user is eligible to vote

    return 0;
}

Solution 📝

#include <stdio.h>

int main() {
    int age = 17;
    char nationality = 'I'; // 'I' for Indian, 'F' for Foreign

    if (age >= 18 && (nationality == 'I' || (nationality == 'F' && age >= 18 && nationality == 'PR'))){
        printf("The user is eligible to vote.\n");
    } else {
        printf("The user is not eligible to vote.\n");
    }

    return 0;
}

Congratulations! You've mastered C Logical Operators. Keep practicing, and soon you'll be able to create powerful and complex conditions in your C programs. Happy coding! 🎉