# 2695. Array Wrapper

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

[2695. Array Wrapper](https://leetcode.com/problems/array-wrapper/)

### 題目描述

Create a class `ArrayWrapper` that accepts an array of integers in it's constructor. This class should have two features:

- When two instances of this class are added together with the `+` operator, the resulting value is the sum of all the elements in both arrays.
- When the `String()` function is called on the instance, it will return a comma separated string surrounded by brackets. For example, `[1,2,3]`.

### 範例

**Example 1:**

Input: nums = [[1,2],[3,4]], operation = "Add"
Output: 10
Explanation:
const obj1 = new ArrayWrapper([1,2]);
const obj2 = new ArrayWrapper([3,4]);
obj1 + obj2; // 10

**Example 2:**

Input: nums = [[23,98,42,70]], operation = "String"
Output: "[23,98,42,70]"
Explanation:
const obj = new ArrayWrapper([23,98,42,70]);
String(obj); // "[23,98,42,70]"

**Example 3:**

Input: nums = [[],[]], operation = "Add"
Output: 0
Explanation:
const obj1 = new ArrayWrapper([]);
const obj2 = new ArrayWrapper([]);
obj1 + obj2; // 0

**Constraints**:

- `0 <= nums.length <= 1000`
- `0 <= nums[i] <= 1000`
- `Note: nums is the array passed to the constructor`

### 解答

#### TypeScript

class ArrayWrapper {
  private nums: number[];

  constructor(nums: number[]) {
    this.nums = nums;
  }

  valueOf() {
    return this.nums.reduce((a, b) => a + b, 0);
  }

  toString() {
    return `[${this.nums.join(',')}]`;
  }
}

> [name=Sheep][time=Thur, June 1, 2023]

### Reference

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