Max By

easycodingJavaScriptArraysFunctions~10 min

Asked at Google, Meta, Amazon

Overview

Implement maxBy(array, iteratee) — returns element with largest iteratee value.

Examples

maxBy([{n:1},{n:2}], o => o.n); // {n:2}

Solution

Reveal solution

function maxBy(array, iteratee) {
  if (!array.length) return undefined;
  let max = array[0], maxV = iteratee(array[0]);
  for (let i = 1; i < array.length; i++) {
    const v = iteratee(array[i]);
    if (v > maxV) { maxV = v; max = array[i]; }
  }
  return max;
}

max-by.js

Max By

easycodingJavaScriptArrays

Overview

Implement maxBy(array, iteratee) — returns element with largest iteratee value.

Examples

maxBy([{n:1},{n:2}], o => o.n); // {n:2}

Solution

Reveal solution

function maxBy(array, iteratee) {
  if (!array.length) return undefined;
  let max = array[0], maxV = iteratee(array[0]);
  for (let i = 1; i < array.length; i++) {
    const v = iteratee(array[i]);
    if (v > maxV) { maxV = v; max = array[i]; }
  }
  return max;
}

NameTopicDifficulty

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103 of 103 problems