# 2619. Array Prototype Last

###### tags: `leetcode 30 days js challenge` `Easy`

[2619. Array Prototype Last](https://leetcode.com/problems/array-prototype-last/)

### 題目描述

Write code that enhances all arrays such that you can call the `array.last()` method on any array and it will return the last element. If there are no elements in the array, it should return `-1`.

### 範例

**Example 1:**

Input: nums = [1,2,3]
Output: 3
Explanation: Calling nums.last() should return the last element: 3.

**Example 2:**

Input: nums = []
Output: -1
Explanation: Because there are no elements, return -1.

**Constraints**:

- `0 <= arr.length <= 1000`
- `0 <= arr[i] <= 1000`

### 解答

#### TypeScript

declare global {
  interface Array<T> {
    last(): T | -1;
  }
}

Array.prototype.last = function() {
  return this.length === 0 ? -1 : this[this.length - 1];
};

> [name=Sheep][time=Sat, May 27, 2023]

### Reference

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