var t1 = [];
var t2 = [];
var arr = [
  {
    id: 1,
    name: 'a1'
  },
  {
    id: 2,
    name: 'a2'
  },
  {
    id: 3,
    name: 'a3'
  }
]

function test(id, name) {
  this.id = id
  this.name = name
  this.idAndName = id + name
}

arr.forEach((item, index) => {
  // 写法1，直接添加
  t1.push({
    id: item.id,
    name: item.name,
    idAndName: item.id + item.name
  })

  // 写法2，通过new的方式添加
  t2.push(new test(item.id, item.name));
})
console.log(t1, t2);

上面的两种写法哪种方式好些？有什么区别