Nested conditional statements - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of nested if-else with integer input

What is the output of the following C code when num = 7?

C

#include <stdio.h>

int main() {
    int num = 7;
    if (num > 5) {
        if (num < 10) {
            printf("A\n");
        } else {
            printf("B\n");
        }
    } else {
        printf("C\n");
    }
    return 0;
}

A B

B C

C A

D No output

💡 Hint

Check the conditions step by step starting from the outer if.

The outer if checks if num > 5, which is true for 7. Then the inner if checks if num < 10, which is also true. So it prints 'A'.

❓ Predict Output

intermediate

Output of nested if-else with character input

What will be printed when the variable ch = 'b' is used in this code?

C

#include <stdio.h>

int main() {
    char ch = 'b';
    if (ch == 'a') {
        printf("Apple\n");
    } else {
        if (ch == 'b') {
            printf("Banana\n");
        } else {
            printf("Cherry\n");
        }
    }
    return 0;
}

A Banana

B Cherry

C Apple

D No output

💡 Hint

Check the first if condition and then the nested else-if.

The first if is false because ch is 'b', not 'a'. The else block contains another if that checks if ch == 'b', which is true, so it prints 'Banana'.

🔧 Debug

advanced

Identify the error in nested if-else code

What error will this code produce when compiled?

C

#include <stdio.h>

int main() {
    int x = 10;
    if (x > 5)
        if (x < 15)
            printf("Inside\n");
        else
            printf("Outside\n");
    return 0;
}

A Syntax error due to missing braces

B Runtime error

C No error, prints "Outside"

D No error, prints "Inside"

💡 Hint

Remember how else matches the nearest if without braces.

The else matches the inner if (x < 15). Since x=10, the condition is true, so it prints "Inside". No syntax or runtime error occurs.

🧠 Conceptual

advanced

Number of times inner block executes

Consider the code below. How many times will the inner printf("Hello\n") execute?

C

#include <stdio.h>

int main() {
    int i;
    for (i = 0; i < 5; i++) {
        if (i % 2 == 0) {
            if (i > 1) {
                printf("Hello\n");
            }
        }
    }
    return 0;
}

A 4

B 2

C 3

D 1

💡 Hint

Check values of i that are even and greater than 1.

i takes values 0,1,2,3,4. Even values are 0,2,4. Among these, i > 1 is true for 2 and 4. So the inner printf runs twice.

❓ Predict Output

expert

Output of nested if-else with multiple conditions

What is the output of this code snippet?

C

#include <stdio.h>

int main() {
    int a = 3, b = 7, c = 5;
    if (a > b) {
        if (b > c) {
            printf("X\n");
        } else {
            printf("Y\n");
        }
    } else {
        if (a > c) {
            printf("Z\n");
        } else {
            printf("W\n");
        }
    }
    return 0;
}

A W

B Z

C X

D Y

💡 Hint

Evaluate conditions stepwise: a > b, then b > c, then a > c.

a=3, b=7, c=5. a > b is false, so else block runs. Then a > c is false (3 > 5 is false), so it prints "W".