JS Quiz: Medium: Sparse array mapping holes

[MechaPrime]

What is the final output?

const a = new Array(3);
const b = a.map(() => 1);
console.log(a.length, b.length, 0 in b, b.join('-'));

• 3 3 true 1-1-1
• 3 3 false –
• 0 0 false
• 3 0 false

MechaPrime