If–else statement in C - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of nested if–else

What is the output of this C code snippet?

C

int main() {
    int x = 5, y = 10;
    if (x > y) {
        printf("A\n");
    } else if (x == y) {
        printf("B\n");
    } else {
        printf("C\n");
    }
    return 0;
}

A B

B A

C C

D No output

💡 Hint

Compare the values of x and y carefully.

Since x (5) is less than y (10), the else block runs, printing 'C'.

❓ Predict Output

intermediate

If–else with logical operators

What will this program print?

C

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

A Y

B No output

C X

D Compilation error

💡 Hint

Check both conditions in the if statement.

a > 0 is true but b < 5 is false (b=7), so the if condition is false and else runs.

❓ Predict Output

advanced

If–else with assignment inside condition

What is the output of this code?

C

int main() {
    int x = 0;
    if (x = 5) {
        printf("Hello\n");
    } else {
        printf("World\n");
    }
    return 0;
}

A World

B Hello

C Compilation error

D No output

💡 Hint

Remember that assignment inside if condition returns the assigned value.

The assignment x = 5 returns 5, which is true, so the if block runs printing 'Hello'.

❓ Predict Output

advanced

If–else with multiple conditions and else

What will this program print?

C

int main() {
    int n = 0;
    if (n > 0) {
        printf("Positive\n");
    } else if (n < 0) {
        printf("Negative\n");
    } else {
        printf("Zero\n");
    }
    return 0;
}

A Negative

B No output

C Positive

D Zero

💡 Hint

Check the value of n and which condition matches.

Since n is 0, neither n > 0 nor n < 0 is true, so else runs printing 'Zero'.

❓ Predict Output

expert

If–else with uninitialized variable

What error or output does this code produce?

C

int main() {
    int x;
    if (x > 0) {
        printf("Positive\n");
    } else {
        printf("Non-positive\n");
    }
    return 0;
}

A Undefined behavior (may print anything)

B Non-positive

C Compilation error

D Positive

💡 Hint

Consider what happens when you use a variable without setting it first.

Variable x is uninitialized, so its value is garbage. Using it in condition causes undefined behavior.