JS Practice — Built-in Objects

Array.prototype.length — truncate by setting length

📖 Usage Example

const arr = [1, 2, 3, 4, 5]
arr.length = 3
arr  // → [1, 2, 3]  (elements truncated)

Assign a smaller value to length to truncate an array in place.

Array.prototype.length — truncation

You can shorten an array by assigning a smaller value to its length property. Elements beyond the new length are removed and the array is mutated in place.

Challenge: Implement truncate(arr, n) that sets arr.length = n and returns the (now shorter) array.

truncate([1, 2, 3, 4, 5], 3) // → [1, 2, 3]
truncate([1, 2, 3], 0)       // → []

💡 Hints (2)

• Assigning to `arr.length` mutates the array in place.
• Setting `arr.length = 0` is a common way to empty an array while keeping the same reference.