Else–if ladder in C++ - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to check if the number is positive.

C++

#include <iostream>
using namespace std;

int main() {
    int num = 10;
    if (num [1] 0) {
        cout << "Positive number" << endl;
    }
    return 0;
}

Drag options to blanks, or click blank then click option'

A!=

B==

C>

D<

Attempts:

3 left

💡 Hint

Common Mistakes

Using '==' instead of '>' to check positivity.

Using '<' which checks for negative numbers.

The condition num > 0 checks if the number is positive.

2fill in blank

medium

Complete the else-if ladder to check if a number is negative.

C++

#include <iostream>
using namespace std;

int main() {
    int num = -5;
    if (num > 0) {
        cout << "Positive" << endl;
    } else if (num [1] 0) {
        cout << "Negative" << endl;
    } else {
        cout << "Zero" << endl;
    }
    return 0;
}

Drag options to blanks, or click blank then click option'

A<

B==

C>=

D!=

Attempts:

3 left

💡 Hint

Common Mistakes

Using '==' which only checks for zero.

Using '>=' which includes zero and positive numbers.

The condition num < 0 checks if the number is negative.

3fill in blank

hard

Fix the error in the else-if ladder condition to correctly check for zero.

C++

#include <iostream>
using namespace std;

int main() {
    int num = 0;
    if (num > 0) {
        cout << "Positive" << endl;
    } else if (num [1] 0) {
        cout << "Zero" << endl;
    } else {
        cout << "Negative" << endl;
    }
    return 0;
}

Drag options to blanks, or click blank then click option'

A==

B<

C>

D!=

Attempts:

3 left

💡 Hint

Common Mistakes

Using '<' or '>' which check for negative or positive numbers.

Using '!=' which checks for not equal, not zero.

The condition num == 0 correctly checks if the number is zero.

4fill in blank

hard

Fill both blanks to complete the else-if ladder that prints the number's sign.

C++

#include <iostream>
using namespace std;

int main() {
    int num = -3;
    if (num [1] 0) {
        cout << "Positive" << endl;
    } else if (num [2] 0) {
        cout << "Negative" << endl;
    } else {
        cout << "Zero" << endl;
    }
    return 0;
}

Drag options to blanks, or click blank then click option'

A>

B<

C==

D!=

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping the operators in the conditions.

Using '==' or '!=' in the first two conditions.

The first condition checks if num > 0 (positive), the second checks if num < 0 (negative).

5fill in blank

hard

Fill all three blanks to create an else-if ladder that prints "Positive", "Negative", or "Zero" based on the number.

C++

#include <iostream>
using namespace std;

int main() {
    int num = 0;
    if (num [1] 0) {
        cout << "Positive" << endl;
    } else if (num [2] 0) {
        cout << "Negative" << endl;
    } else if (num [3] 0) {
        cout << "Zero" << endl;
    }
    return 0;
}

Drag options to blanks, or click blank then click option'

A>

B<

C==

D!=

Attempts:

3 left

💡 Hint

Common Mistakes

Using '!=' instead of '==' for zero check.

Mixing up the order of conditions.

The conditions check if num > 0 (positive), num < 0 (negative), and num == 0 (zero).