js给数组中对象添加新属性

let person =[{
  id: 1,
  name: 'vhen'
},{

  id: 2,
  name: 'json'
}]

let newArr = obj.map((item,index) =>{
   return Object.assign(item,{index:index})
})

var a =[{name: 'Tom',age:20},{name: 'Tom2',age:22}]

a[0]['gender']='women'
a[0]['address']="China"
a[1].province="Jiangsu"

var a = [{name:'dede'},{name:'jeen'}];
var b = [{age:'18'},{age:'19'},{age:'20'}];
var c = 'age';
merge(a,b,c);
console.log(a)


function merge(a,b,attrName){
let attr = attrName
b.map((value,index)=>{
//数组b 长度大于a的长度时，需要判断
if(a[index] !== undefined){
a[index][attr] = value[attr]
} else{
return
}
})
return a
}

Array [Object { name: "dede", age: "18" }, Object { name: "jeen", age: "19" }]

var obj1={'a':1};
var obj2={'b':2,'c':3};
for(var key in obj2){
     if(obj2.hasOwnProperty(key)===true){//此处hasOwnProperty是判断自有属性，用 for in 循环遍历对象的属性时，原型链上的所有属性都将被访问会避免原型对象扩展带来的干扰
           obj1[key]=obj2[key];
} 
}
 
console.log(obj1);//{'a':1,'b':2,'c':3};

let resultList = [{"name":"a1"},{"name":"b1"}]
resultList.forEach(tem => {
    tem.age = 1;
})

let resultList = [{"name":"a1","shapes":[{"age":12,"sex":"female"}]},{"name":"b1","shapes":[{"age":10,"sex":"male"}]}]
resultList.forEach(item => {
    item.shapes.forEach(tem => {
        tem.class = "1";
    })
})