알고리즘/과제
[Array] Array Prototype Last
lazyhysong
2023. 7. 3. 17:25
https://leetcode.com/problems/array-prototype-last/
Array Prototype Last - LeetCode
Can you solve this real interview question? 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 retur
leetcode.com
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.
You may assume the array is the output of JSON.parse.
Example 1:
Input: nums = [null, {}, 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.
solution
Array.prototype.last = function() {
const length = this.length;
return length > 0 ? this[length - 1] : -1;
};
/**
* const arr = [1, 2, 3];
* arr.last(); // 3
*/
typescript
declare global {
interface Array<T> {
last(): T | -1;
}
}
Array.prototype.last = function() {
if(!this.length) return -1;
return this[this.length - 1];
};
/**
* const arr = [1, 2, 3];
* arr.last(); // 3
*/
export {};