Switch vs if comparison in Javascript - Practice Questions

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of switch with fall-through

What is the output of this JavaScript code?

const value = 2;
switch(value) {
  case 1:
    console.log('One');
  case 2:
    console.log('Two');
  case 3:
    console.log('Three');
    break;
  default:
    console.log('Default');
}

Javascript

const value = 2;
switch(value) {
  case 1:
    console.log('One');
  case 2:
    console.log('Two');
  case 3:
    console.log('Three');
    break;
  default:
    console.log('Default');
}

A Two\nThree\nDefault

B Two\nThree

C One\nTwo\nThree

D Default

💡 Hint

Remember that without break, switch cases fall through to the next.

Since there is no break after case 2, it runs case 2 and case 3's console.logs, then stops at break.

❓ Predict Output

intermediate

Equivalent if-else output

What is the output of this if-else code?

const value = 2;
if (value === 1) {
  console.log('One');
} else if (value === 2) {
  console.log('Two');
} else if (value === 3) {
  console.log('Three');
} else {
  console.log('Default');
}

Javascript

const value = 2;
if (value === 1) {
  console.log('One');
} else if (value === 2) {
  console.log('Two');
} else if (value === 3) {
  console.log('Three');
} else {
  console.log('Default');
}

A Default

B Two\nThree

C One

D Two

💡 Hint

Only one block runs in if-else chains.

The value matches the second condition, so only 'Two' is printed.

❓ Predict Output

advanced

Switch with multiple cases combined

What will this code print?

const fruit = 'apple';
switch(fruit) {
  case 'banana':
  case 'apple':
    console.log('Yellow or Red fruit');
    break;
  case 'orange':
    console.log('Orange fruit');
    break;
  default:
    console.log('Unknown fruit');
}

Javascript

const fruit = 'apple';
switch(fruit) {
  case 'banana':
  case 'apple':
    console.log('Yellow or Red fruit');
    break;
  case 'orange':
    console.log('Orange fruit');
    break;
  default:
    console.log('Unknown fruit');
}

A Yellow or Red fruit

B Orange fruit

C Unknown fruit

D banana

💡 Hint

Cases stacked without break share the same code block.

Both 'banana' and 'apple' cases run the same console.log because they share the block.

❓ Predict Output

advanced

If vs switch with type coercion

What is the output of this code?

const val = '2';
switch(val) {
  case 2:
    console.log('Number 2');
    break;
  case '2':
    console.log('String 2');
    break;
  default:
    console.log('Default');
}

Javascript

const val = '2';
switch(val) {
  case 2:
    console.log('Number 2');
    break;
  case '2':
    console.log('String 2');
    break;
  default:
    console.log('Default');
}

A String 2

B Default

C Number 2

D TypeError

💡 Hint

Switch uses strict equality (===) for matching.

The value is a string '2', so only case '2' matches exactly.

🧠 Conceptual

expert

Why prefer switch over if in some cases?

Which of the following is the best reason to use a switch statement instead of multiple if-else statements in JavaScript?

A Switch statements automatically break after each case without needing a break statement.

B Switch statements can evaluate complex expressions better than if-else.

C Switch statements improve readability when checking one variable against many constant values.

D Switch statements allow asynchronous code execution inside cases.

💡 Hint

Think about how code looks when checking many values of one variable.

Switch is clearer and easier to read when testing one variable against many fixed values.