Comments in JavaScript

Code Quality: Comments

How do you reduce the number of unnecessary comments in your code?

View Answer:

Interview Response: The key to reducing unnecessary comments in your code is to write self-descriptive code. The best way to achieve this is to replace a chunk of code with a function.

Code Example: Confusing Code

function showPrimes(n) {
  nextPrime: for (let i = 2; i < n; i++) {
    // check if i is a prime number   <-- this is an unnecessary comment
    for (let j = 2; j < i; j++) {
      if (i % j == 0) continue nextPrime;
    }

    alert(i);
  }
}

Code Example: Good Code

// The better variant, with a factored-out function isPrime:
function showPrimes(n) {
  for (let i = 2; i < n; i++) {
    if (!isPrime(i)) continue;

    alert(i);
  }
}

function isPrime(n) {
  for (let i = 2; i < n; i++) {
    if (n % i == 0) return false;
  }

  return true;
}

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What are Good comments in JavaScript?

View Answer:

Interview Response: Good comments describe the architecture and lean less toward explaining what the code is doing. Good comments provide the team with a high-level overview of the components and how they interact. Good comments give a bird's eye view of the code. Good comments include documenting function parameters and their usage as well.

Code Example:

/**
 * Returns x raised to the n-th power.
 *
 * @param {number} x The number to raise.
 * @param {number} n The power, must be a natural number.
 * @return {number} x raised to the n-th power.
 */
function pow(x, n) {
  ...
}

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