给数组对象中每一个对象添加一个字段

let list = [{name:'小李',age:'12'},{name:'小明',age:'12'}]
list.forEach((value , index) => {
    value['num'] = ''
})

console.log(list)//[{name:'小李',age:'12',num:''},{name:'小明',age:'12',num:''}]