JS Practice — Built-in Objects

Array.prototype.entries() — combine arrays into an object

📖 Usage Example

const arr = ['a', 'b', 'c']
const obj = Object.fromEntries(arr.entries())
// → { 0: 'a', 1: 'b', 2: 'c' }

Pass entries() to Object.fromEntries() to convert an array into an indexed object.

Array.prototype.entries() — creating key-value maps

You can use entries() on a keys array to pair indices with values from a parallel values array, building an object map.

Challenge: Implement arrayToObject(keys, vals) that combines two parallel arrays into a plain object using entries().

arrayToObject(['a', 'b', 'c'], [1, 2, 3]) // → { a: 1, b: 2, c: 3 }

💡 Hints (2)

• Iterate over `keys.entries()` to get `[index, key]` — then use `vals[index]` for the value.
• You can also use `Object.fromEntries(keys.map((k, i) => [k, vals[i]]))` for a one-liner.