Switch statement - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of switch with fall-through

What is the output of this C code snippet?

C

#include <stdio.h>

int main() {
    int x = 2;
    switch (x) {
        case 1:
            printf("One\n");
        case 2:
            printf("Two\n");
        case 3:
            printf("Three\n");
            break;
        default:
            printf("Default\n");
    }
    return 0;
}

A

Two

B

One
Two
Three

C

Two
Three

D

Default

💡 Hint

Remember that cases fall through unless you use break.

Since x is 2, execution starts at case 2 and continues until a break is found. So it prints "Two" and "Three".

❓ Predict Output

intermediate

Value of variable after switch

What is the value of variable result after running this code?

C

#include <stdio.h>

int main() {
    int code = 3;
    int result = 0;
    switch (code) {
        case 1:
            result = 10;
            break;
        case 2:
            result = 20;
            break;
        case 3:
            result = 30;
        case 4:
            result += 5;
            break;
        default:
            result = -1;
    }
    printf("%d\n", result);
    return 0;
}

A 35

B 30

C -1

D 20

💡 Hint

Check if there is a break after case 3.

Since case 3 has no break, execution falls through to case 4, adding 5 to result (30 + 5 = 35).

❓ Predict Output

advanced

Output with multiple cases combined

What is the output of this program?

C

#include <stdio.h>

int main() {
    int day = 5;
    switch (day) {
        case 1:
        case 2:
        case 3:
            printf("Weekday\n");
            break;
        case 4:
        case 5:
            printf("Almost weekend\n");
            break;
        case 6:
        case 7:
            printf("Weekend\n");
            break;
        default:
            printf("Invalid day\n");
    }
    return 0;
}

A

Weekend

B

Almost weekend

C

Weekday

D

Invalid day

💡 Hint

Cases 4 and 5 share the same code block.

Since day is 5, it matches case 5, which prints "Almost weekend".

❓ Predict Output

advanced

Error caused by invalid switch expression type

What error will this code produce when compiled?

C

#include <stdio.h>

int main() {
    float value = 2.5;
    switch (value) {
        case 1.0:
            printf("One\n");
            break;
        case 2.5:
            printf("Two point five\n");
            break;
        default:
            printf("Default\n");
    }
    return 0;
}

A Compile error: switch expression must be an integer type

B Runtime error: invalid case label

C Output: Two point five

D Output: Default

💡 Hint

Check the type allowed in switch expressions in C.

In C, the switch expression must be an integer type. Using float causes a compile error.

🧠 Conceptual

expert

Number of times default executes in nested switches

Consider this nested switch code. How many times will the default case print "Default" when outer = 1 and inner = 3?

C

#include <stdio.h>

int main() {
    int outer = 1;
    int inner = 3;
    switch (outer) {
        case 1:
            switch (inner) {
                case 1:
                    printf("Inner One\n");
                    break;
                case 2:
                    printf("Inner Two\n");
                    break;
                default:
                    printf("Default\n");
            }
            break;
        default:
            printf("Default\n");
    }
    return 0;
}

A 3

B 2

C 0

D 1

💡 Hint

Check which switch executes default with given values.

The outer switch matches case 1, so it does not print default. The inner switch with inner=3 hits default once, printing "Default" once.