Question

What's the output?

let num = 10;

const increaseNumber = () => num++;
const increasePassedNumber = number => number++;

const num1 = increaseNumber();
const num2 = increasePassedNumber(num1);

console.log(num1);
console.log(num2);

• A: 10, 10
• B: 10, 11
• C: 11, 11
• D: 11, 12

Answer 1

Answer: A

The unary operator ++ first returns the value of the operand, then increments the value of the operand. The value of num1 is 10, since the increaseNumber function first returns the value of num, which is 10, and only increments the value of num afterwards.

num2 is 10, since we passed num1 to the increasePassedNumber. number is equal to 10(the value of num1). Again, the unary operator ++ first returns the value of the operand, then increments the value of the operand. The value of number is 10, so num2 is equal to 10.