for...in vs for...of — JS Technical Interview Questions & Answers

Side-by-side comparison table.

for...in vs for...of

  • for...in vs for...of (diff) is a JS topic. In plain words you use it for a short for...in vs for...of diff example in a script in the browser. Don’t start with a slogan — start with that picture.
  • Smallest example: the smallest for...in vs for...of diff example you can type. Type it, run it, and say what you see. If you can do that from memory, you know for...in vs for...of (diff).
  • From the example next to this theory: Side-by-side comparison table.
  • Trap: only saying “for...in vs for...of diff” with no example. Fix that before you talk about advanced JS.
  • Viva: what is for...in vs for...of (diff)? Then show the smallest for...in vs for...of diff example you can type. Then name the trap.

Technical Interview Tip: What is for...in vs for...of (diff)? Show this: the smallest for...in vs for...of diff example you can type. Trap: only saying “for...in vs for...of diff” with no example.

Code Examples for for...in vs for...of

for...in vs for...of — working example

for (let i = 1; i <= 3; i++) {
  if (i === 2) continue;
  console.log("for", i);
}

let n = 3;
while (n > 0) {
  console.log("while", n);
  n -= 1;
}

const user = { name: "Ada", city: "Pune" };
for (const key in user) console.log(key, user[key]);

for (const ch of "JS") console.log(ch);

for...in vs for...of — for/while/do-while repeat work; for...in walks keys; for...of walks iterable values.

How to Explain for...in vs for...of to an Interviewer

What is for...in vs for...of (diff)?

Used for a short for...in vs for...of diff example a script in the browser Not just the heading

Give one small example of for...in vs for...of (diff).

the smallest for...in vs for...of diff example you can type Side-by-side comparison table

What mistake do beginners make with for...in vs for...of (diff)?

only saying “for...in vs for...of diff” with no example Show the fix

Where do you use for...in vs for...of (diff)?

a script in the browser a short for...in vs for...of diff example