2619. Array Prototype Last
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.
Example 1:
Example 2:
Constraints:
- 0 <= arr.length <= 1000
- 0 <= arr[i] <= 1000
From: LeetCode
Link: 2619. Array Prototype Last
Solution:
Ideas：
This code adds a last function to the Array prototype which means all arrays will have this function. The function checks if the array has any elements (this.length > 0). If it does, it returns the last element (this[this.length - 1]). If it doesn’t, it returns -1.
Code:
Array.prototype.last = function() {
return this.length > 0 ? this[this.length - 1] : -1;
};
/**
* const arr = [1, 2, 3];
* arr.last(); // 3
*/