Question

Which of these methods modifies the original array?

const emojis = ['✨', '', ''];

emojis.map(x => x + '✨');
emojis.filter(x => x !== '');
emojis.find(x => x !== '');
emojis.reduce((acc, cur) => acc + '✨');
emojis.slice(1, 2, '✨');
emojis.splice(1, 2, '✨');

• A: All of them
• B: map reduce slice splice
• C: map slice splice
• D: splice

Answer 1

Answer: D

With splice method, we modify the original array by deleting, replacing or adding elements. In this case, we removed 2 items from index 1 (we removed '' and '') and added the ✨ emoji instead.

map, filter and slice return a new array, find returns an element, and reduce returns a reduced value.