js循环改变id的值

Question

    const arrs = [
        {id:1,username:"张三",userage:18,num:3},
    ]
    const res = []
    arrs.forEach(item=>{
       for(var i = 0; i<item.num; i++){
           res.push(item)
       }
    })
    
    打印的res
    0: {id: 1, username: "张三", userage: 18, num: 3}
    1: {id: 1, username: "张三", userage: 18, num: 3}
    2: {id: 1, username: "张三", userage: 18, num: 3}

   需求：如何把id改变
    0: {id: 1, username: "张三", userage: 18, num: 3}
    1: {id: 2, username: "张三", userage: 18, num: 3}
    2: {id: 3, username: "张三", userage: 18, num: 3}

Answer 1

  const arrs = [
    { id: 1, username: "张三", userage: 18, num: 3 },
  ]
  const res = []
  arrs.forEach((item, index) => {
    for (var i = 0; i < item.num; i++) {
      res.push({
        ...item,
        id: i + 1
      })
    }
  })

  console.log(res);