Lab: Conditional Statement

1. If Statement

Problem Statement:
Write a program that checks whether a given number is divisible by 5.

• Input: An integer.
• Output: Print “Divisible by 5” if the number is divisible by 5.

#include <stdio.h>

int main() {
    int num;
    printf("Enter an integer: ");
    scanf("%d", &num);
    
    if (num % 5 == 0) {
        printf("Divisible by 5\n");
    }
    
    return 0;
}

Sample Input:
25

Sample Output:
Divisible by 5

2. If-Else Statement

Problem Statement:
Write a program to check if a number is positive or negative.

• Input: An integer.
• Output: Print “Positive” if the number is positive, otherwise print “Negative”.

#include <stdio.h>

int main() {
    int num;
    printf("Enter an integer: ");
    scanf("%d", &num);
    
    if (num >= 0) {
        printf("Positive\n");
    } else {
        printf("Negative\n");
    }
    
    return 0;
}

Sample Input:
-3

Sample Output:
Negative

3. Else-If Ladder

Problem Statement:
Write a program that reads the percentage of a student and prints the grade based on the following criteria:

• Grade A: 90% and above
• Grade B: 80% – 89%
• Grade C: 70% – 79%
• Grade D: 60% – 69%
• Grade F: Below 60%
• Input: Percentage (a float value).
• Output: Print the grade.

#include <stdio.h>

int main() {
    float percentage;
    printf("Enter the percentage: ");
    scanf("%f", &percentage);
    
    if (percentage >= 90) {
        printf("Grade A\n");
    } else if (percentage >= 80) {
        printf("Grade B\n");
    } else if (percentage >= 70) {
        printf("Grade C\n");
    } else if (percentage >= 60) {
        printf("Grade D\n");
    } else {
        printf("Grade F\n");
    }
    
    return 0;
}

Sample Input:
85.5

Sample Output:
Grade B

4. If-Else with Multiple Conditions

Problem Statement:
Write a program to determine if a given year is a leap year. A year is a leap year if it is divisible by 4, but if it is divisible by 100, it must also be divisible by 400.

• Input: A year (an integer).
• Output: Print “Leap year” if the year is a leap year, otherwise print “Not a leap year”.

#include <stdio.h>

int main() {
    int year;
    printf("Enter a year: ");
    scanf("%d", &year);
    
    if (year % 4 == 0) {
        if (year % 100 == 0) {
            if (year % 400 == 0) {
                printf("Leap year\n");
            } else {
                printf("Not a leap year\n");
            }
        } else {
            printf("Leap year\n");
        }
    } else {
        printf("Not a leap year\n");
    }
    
    return 0;
}

Sample Input:
2000

Sample Output:
Leap year

5. Switch Statement

Problem Statement:
Write a program that takes a day number (1 for Monday, 2 for Tuesday, …, 7 for Sunday) and prints the name of the day using a switch statement.

• Input: An integer (1-7).
• Output: Print the day of the week.

#include <stdio.h>

int main() {
    int day;
    printf("Enter day number (1-7): ");
    scanf("%d", &day);
    
    switch (day) {
        case 1: printf("Monday\n"); break;
        case 2: printf("Tuesday\n"); break;
        case 3: printf("Wednesday\n"); break;
        case 4: printf("Thursday\n"); break;
        case 5: printf("Friday\n"); break;
        case 6: printf("Saturday\n"); break;
        case 7: printf("Sunday\n"); break;
        default: printf("Invalid day\n");
    }
    
    return 0;
}

Sample Input:
3

Sample Output:
Wednesday

6. Switch Statement with Arithmetic Operations

Problem Statement:
Write a program that asks the user to enter two numbers and a character representing an operation (‘+’, ‘-‘, ‘*’, ‘/’). Use a switch statement to perform the corresponding arithmetic operation and display the result.

• Input: Two integers and a character (+, -, *, /).
• Output: Print the result of the arithmetic operation.

#include <stdio.h>

int main() {
    int num1, num2;
    char operation;
    
    printf("Enter first number: ");
    scanf("%d", &num1);
    
    printf("Enter second number: ");
    scanf("%d", &num2);
    
    printf("Enter operation (+, -, *, /): ");
    scanf(" %c", &operation);
    
    switch (operation) {
        case '+':
            printf("Result: %d\n", num1 + num2);
            break;
        case '-':
            printf("Result: %d\n", num1 - num2);
            break;
        case '*':
            printf("Result: %d\n", num1 * num2);
            break;
        case '/':
            if (num2 != 0) {
                printf("Result: %d\n", num1 / num2);
            } else {
                printf("Error: Division by zero\n");
            }
            break;
        default:
            printf("Invalid operation\n");
    }
    
    return 0;
}

Sample Input:
Enter first number: 10 Enter second number: 5 Enter operation (+, -, *, /): *

Sample Output:
Result: 50

7. If-Else with Nested Conditions

Problem Statement:
Write a program to check if a student is eligible for a scholarship. The student is eligible if:

• The student has secured more than 85% in the exam and the family income is less than 5,00,000.
• Otherwise, the student is not eligible.
• Input: Percentage and family income.
• Output: Print “Eligible for scholarship” or “Not eligible for scholarship”.

#include <stdio.h>

int main() {
    float percentage;
    long income;
    
    printf("Enter the percentage: ");
    scanf("%f", &percentage);
    
    printf("Enter family income: ");
    scanf("%ld", &income);
    
    if (percentage > 85) {
        if (income < 500000) {
            printf("Eligible for scholarship\n");
        } else {
            printf("Not eligible for scholarship\n");
        }
    } else {
        printf("Not eligible for scholarship\n");
    }
    
    return 0;
}

Sample Input:
Percentage: 90 Income: 450000

Sample Output:
Eligible for scholarship

8. Conditional (Ternary) Operator

Problem Statement: Write a C program that takes two integers as input and uses the conditional (ternary) operator to find and print the larger of the two numbers.

Input: Two integers.

Output: Print the larger number using a single line of code with the conditional (ternary) operator.

#include <stdio.h>

int main() {
    int num1, num2, larger;

    // Input: Two integers
    printf("Enter first number: ");
    scanf("%d", &num1);
    printf("Enter second number: ");
    scanf("%d", &num2);

    // Using conditional (ternary) operator to find the larger number
    larger = (num1 > num2) ? num1 : num2;

    // Output: The larger number
    printf("The larger number is: %d\n", larger);

    return 0;
}

Sample Input:
Enter first number: 8 Enter second number: 12

Sample Output:
The larger number is: 12

Hint:
You should use the syntax:
condition ? true_expression : false_expression;