es实用新方法

1、Promise.withResolvers()
Promise.withResolvers() 允许创建一个新的 Promise，并同时获得 resolve 和 reject 函数。

// 以前实现方法
let resolve, reject;  
const promise = new Promise((res, rej) => {  
    resolve = res;  
    reject = rej;  
});
// Promise.withResolvers()实现方法
const { promise, resolve, reject } = Promise.withResolvers();  
// 在这里可以使用 resolve 和 reject 函数  
setTimeout(() => resolve('成功！'), 1000);  
  
promise.then(value => {  
    console.log(value); // 输出: 成功！  
});

2、Object.groupBy()
Object.groupBy()方法用于数组分组。

// 传统实现对象分组
const fruits = [
    { name: "Apple", color: "red" },
    { name: "Banana", color: "yellow" },
    { name: "Cherry", color: "red" },
    { name: "Lemon", color: "yellow" },
    { name: "Grape", color: "purple" },
];

const fruitsByColor = {};

fruits.forEach(fruit => {
    const color = fruit.color;
    if (!fruitsByColor[color]) {
        fruitsByColor[color] = [];
    }
    fruitsByColor[color].push(fruit);
});

console.log(fruitsByColor);

// Object.groupBy()实现对象分组
const fruitsByColor = Object.groupBy(fruits, (fruit) => fruit.color)