One-liner Solutions to 6 Coding Questions in JavaScript
Simple Answers To 6 Coding Questions Asked In JavaScript Interviews
Play this article
Coding questions are an integral part of any JavaScript interview.
There is more than one approach for any question. But, can it be done in a one-liner?
Yes, some questions are pretty straightforward and have a clean solution in a single line of code using ES6 features.
Note that, I am no expert in coming up with such solutions and not at all guaranteeing that they are the ultimate go-to answers for any coding questions.
How to remove duplicates from a sorted array?
const arr = [1, 2, 2, 3, 4, 4, 5];
const filterArray = arr.filter( (item, pos) => arr.indexOf(item) === pos);
console.log(filterArray);
Perform n left rotations in an array
const arr = [1, 2, 3, 4, 5];
const rotate = (arr, rotations = 1) => [...arr.slice(rotations, arr.length), ...arr.slice(0, rotations)];
console.log(rotate(arr, 1));
Find out the second largest element in an unsorted array
const arr = [9, 1, 8, 2, 3, 4, 5];
arr[arr.indexOf(Math.max(...arr))] = Math.max();
console.log(Math.max(...arr));
Find the sum of an array
const arr = [1, 2, 3, 4, 5];
const sum = arr.reduce( (acc, currentVal) => acc += currentVal, 0);
console.log(sum);
Convert the first letter of every word in a string in uppercase.
const str = "i love programming";
return str.split(" ").map((s) => s.charAt(0).toUpperCase() + s.slice(1)).join(' ');
Count the frequency of characters in a string
const s = "samplestring";
const counter = s => [...s].reduce((arr, char) => (arr[char] = arr[char]++ || 1) && arr, {});
console.log(counter);
Thank you for reading.