JSFiddle - React, Tailwind, and code Playground

JavaScript

const data = [{"id": "One", "number": 100}, 
  {"id": "One", "number": 150}, 
  {"id": "One", "number": 200}, 
  {"id": "Two", "number": 50}, 
  {"id": "Two", "number": 100}, 
  {"id": "Three", "number": 10}, 
  {"id": "Three", "number": 90}]

// 自己的写法
let result2 = data.reduce((a, v) => {
  let obj = a.find(i => i.id == v.id);
  if (obj) {
      obj.number += v.number;
  } else {
      a.push(v);
  }
  return a;
}, [])

console.log(result2);
console.log("-------------------------------")