1-Week Frontend Interview Plan

Implement findLast and findLastIndex — scan an array from the end for the last element matching a predicate.

Implement Array.prototype.myAt — return the element at a given index, supporting negative offsets from the end.

Implement Array.prototype.every — return false as soon as an element fails the predicate, true when empty.

Implement Array.prototype.filter from scratch as a method on the array prototype.

Implement Array.prototype.flat — flatten nested arrays to a given depth (default 1, Infinity for all levels), dropping holes.

Implement Array.prototype.forEach — run a callback on each element as (value, index, array), skipping sparse holes.

Implement Array.prototype.includes — test membership with SameValueZero so NaN matches, honoring negative fromIndex.

Implement Array.prototype.indexOf — first index of a value by strict equality, supporting a negative fromIndex.

Implement Array.prototype.some — return true as soon as any element passes the predicate, false when empty.

Implement a custom Array.prototype.square method that returns a new array with each value squared.

Implement a function that splits an array into groups of a given size, with the last group holding the remainder.

Implement a function that constrains a number to lie within an inclusive minimum and maximum range.

Implement a function that returns a new array with every falsy value stripped out.

Implement a function that consolidates rows sharing the same user into a single grouped record.