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

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of nested if–else

What is the output of the following JavaScript code?

Javascript

let x = 10;
if (x > 5) {
  if (x < 15) {
    console.log('A');
  } else {
    console.log('B');
  }
} else {
  console.log('C');
}

A B

B C

C A

D undefined

💡 Hint

Check the conditions step by step.

x is 10, which is greater than 5 and less than 15, so the first if and the nested if both run, printing 'A'.

❓ Predict Output

intermediate

If–else with logical operators

What will this code print to the console?

Javascript

let a = 3;
let b = 7;
if (a > 5 && b < 10) {
  console.log('X');
} else {
  console.log('Y');
}

A X

B Y

C undefined

D SyntaxError

💡 Hint

Remember how && works: both conditions must be true.

a > 5 is false (3 > 5 is false), so the whole condition is false, so else runs printing 'Y'.

❓ Predict Output

advanced

If–else with else if branches

What is the output of this code snippet?

Javascript

let score = 75;
if (score >= 90) {
  console.log('A');
} else if (score >= 80) {
  console.log('B');
} else if (score >= 70) {
  console.log('C');
} else {
  console.log('F');
}

A C

B A

C B

D F

💡 Hint

Check each condition in order.

75 is not >= 90 or 80 but is >= 70, so it prints 'C'.

❓ Predict Output

advanced

If–else with variable reassignment

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

Javascript

let num = 0;
let result;
if (num) {
  result = 'Truthy';
} else {
  result = 'Falsy';
}

A 'Falsy'

B undefined

C 'Truthy'

D ReferenceError

💡 Hint

Remember how JavaScript treats 0 in conditions.

0 is falsy in JavaScript, so else branch runs setting result to 'Falsy'.

❓ Predict Output

expert

If–else with complex condition and side effects

What will be printed by this code?

Javascript

let x = 5;
if ((x += 3) > 7) {
  console.log(x);
} else {
  console.log(x - 1);
}

A 6

B 7

C 5

D 8

💡 Hint

The condition changes x before comparing.

x starts at 5, then x += 3 makes x 8, which is > 7, so it prints 8.