_.groupBy() — JS Technical Interview Questions & Answers

Groups array elements by a key or callback result.

_.groupBy()

  • _.groupBy() (lodash) is a JS topic. In plain words you use it for a short _.groupBy lodash example in a script in the browser. Don’t start with a slogan — start with that picture.
  • Smallest example: the smallest _.groupBy lodash example you can type. Type it, run it, and say what you see. If you can do that from memory, you know _.groupBy() (lodash).
  • From the example next to this theory: Groups array elements by a key or callback result.
  • Trap: only saying “_.groupBy lodash” with no example. Fix that before you talk about advanced JS.
  • Viva: what is _.groupBy() (lodash)? Then show the smallest _.groupBy lodash example you can type. Then name the trap.

Technical Interview Tip: What is _.groupBy() (lodash)? Show this: the smallest _.groupBy lodash example you can type. Trap: only saying “_.groupBy lodash” with no example.

Code Examples for _.groupBy()

_.groupBy() — working example

// Topic: _.groupBy()
const nums = [1, 2, 3];
const doubled = nums.map((n) => n * 2);
console.log(doubled);
console.log(doubled.reduce((a, b) => a + b, 0));

_.groupBy(): map then reduce on [1, 2, 3]. Say both prints.

How to Explain _.groupBy() to an Interviewer

What is _.groupBy() (lodash)?

Used for a short _.groupBy lodash example a script in the browser Not just the heading

Give one small example of _.groupBy() (lodash).

the smallest _.groupBy lodash example you can type Groups array elements by a key or callback result

What mistake do beginners make with _.groupBy() (lodash)?

only saying “_.groupBy lodash” with no example Show the fix

Where do you use _.groupBy() (lodash)?

a script in the browser a short _.groupBy lodash example