C Programming: if else Examples

Code Example of Exercise 1: Even or odd

In this exercise, the program prompts the user to enter an integer. It then uses the modulo operator % to check whether the number is divisible evenly by 2. If the remainder is 0, the number is even; otherwise, it's odd.

#include <stdio.h>

int main() {
    int number;

    // Input the number from the user
    printf("Enter an integer: ");
    scanf("%d", &number);

    // Check if the number is even or odd
    if (number % 2 == 0) {
        printf("%d is even.\n", number);
    } else {
        printf("%d is odd.\n", number);
    }

    return 0;
}

Code Example of Exercise 2: Grading System

#include <stdio.h>

int main() {
    int score;

    printf("Enter the student's score: ");
    scanf("%d", &score);

    if (score >= 90) {
        printf("Grade: A\n");
    } else if (score >= 80) {
        printf("Grade: B\n");
    } else if (score >= 70) {
        printf("Grade: C\n");
    } else if (score >= 60) {
        printf("Grade: D\n");
    } else {
        printf("Grade: F\n");
    }

    return 0;
}

Exercise 3: Calculator Program

In this exercise, the program takes two numbers and an operator as input and uses "if-else" statements to perform the corresponding arithmetic operation. It handles division by zero as well as invalid operators.

int main() {
    float num1, num2;
    char operator;

    printf("Enter the first number: ");
    scanf("%f", &num1);

    printf("Enter an operator (+, -, *, /): ");
    scanf(" %c", &operator);

    printf("Enter the second number: ");
    scanf("%f", &num2);

    if (operator == '+') {
        printf("%.2f + %.2f = %.2f\n", num1, num2, num1 + num2);
    } else if (operator == '-') {
        printf("%.2f - %.2f = %.2f\n", num1, num2, num1 - num2);
    } else if (operator == '*') {
        printf("%.2f * %.2f = %.2f\n", num1, num2, num1 * num2);
    } else if (operator == '/') {
        if (num2 != 0) {
            printf("%.2f / %.2f = %.2f\n", num1, num2, num1 / num2);
        } else {
            printf("Cannot divide by zero.\n");
        }
    } else {
        printf("Invalid operator.\n");
    }

    return 0;
}