If statement in C - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of nested if statements

What is the output of this C code snippet?

C

#include <stdio.h>

int main() {
    int x = 5;
    if (x > 3) {
        if (x < 10) {
            printf("Inside nested if\n");
        }
    } else {
        printf("Outside if\n");
    }
    return 0;
}

A Inside nested if

B Outside if

C No output

D Compilation error

💡 Hint

Check the conditions in the nested if statements carefully.

Since x is 5, it is greater than 3 and less than 10, so the nested if block runs and prints "Inside nested if".

❓ Predict Output

intermediate

Output of if-else with logical operators

What will this program print?

C

#include <stdio.h>

int main() {
    int a = 4, b = 7;
    if (a > 3 && b < 10) {
        printf("Condition met\n");
    } else {
        printf("Condition not met\n");
    }
    return 0;
}

A Condition met

B Condition not met

C Compilation error

D No output

💡 Hint

Both parts of the && operator must be true for the if block to run.

a is 4 (greater than 3) and b is 7 (less than 10), so the condition is true and "Condition met" is printed.

❓ Predict Output

advanced

Output of if statement with assignment inside condition

What is the output of this program?

C

#include <stdio.h>

int main() {
    int x = 0;
    if (x = 5) {
        printf("x is %d\n", x);
    } else {
        printf("x is zero\n");
    }
    return 0;
}

A x is zero

B x is 5

C Compilation error

D No output

💡 Hint

Remember that assignment inside if condition returns the assigned value.

The assignment x = 5 sets x to 5 and returns 5, which is true, so the if block runs and prints "x is 5".

❓ Predict Output

advanced

Output of if statement with missing braces

What will this program print?

C

#include <stdio.h>

int main() {
    int n = 2;
    if (n > 1)
        printf("Greater than one\n");
    printf("Always printed\n");
    return 0;
}

A Compilation error

B Always printed

C Greater than one

D Greater than one\nAlways printed

💡 Hint

Without braces, only the first statement is controlled by if.

Only the first printf is inside the if. The second printf runs always. So both lines print.

🧠 Conceptual

expert

Behavior of if statement with uninitialized variable

What happens when you run this code?

C

#include <stdio.h>

int main() {
    int x;
    if (x) {
        printf("x is true\n");
    } else {
        printf("x is false\n");
    }
    return 0;
}

A Always prints "x is true"

B Always prints "x is false"

C Undefined behavior due to uninitialized variable x

D Compilation error

💡 Hint

Local variables without initialization have unpredictable values.

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