Object对象常用操作

对象的删除

let obj = {a:1, b:2, c:3}
console.log('obj',delete obj.b)

Object.keys()遍历对象,获取对象的属性名,返回由属性名组成的数组

let obj = {a:1, c:3}
console.log(Object.keys(obj))
// ["a", "c"]

Object.values()遍历对象，获取属性值，返回属性值组成的数组

let obj = {a:1, c:3}
console.log(Object.values(obj))
// [1, 3]

obj.hasOwnProperty() 判断对象是否有指定的属性

let obj = {a:1, c:3}
console.log(obj.hasOwnProperty('a'))
// true
console.log('a' in obj)

let obj = {a:1, c:3}
for (key in obj) {
    console.log(key)
}
// a c

// 对象合并，以assign的第一个参数为主
let objOne = {d:4}
Object.assign(obj, objOne)
console.log(obj)

// 过滤对象
 let objnew = Object.keys(obj).filter((e) =>{
     console.log(e)
     // a c d
    return obj[e] > 2
})
console.log(objnew)
// ['c', 'd']

 

js对象的常用操作

   Object.assign(target,...sources)

    target是目标对象

    sources是源对象

    返回目标对象

1，解决 复制一个新对象来操作，旧对象不会改变

    var obj = { a: 1 };
    var copy = Object.assign({}, obj);
    copy.a = 2;
    console.log(obj); //a = 1

 

   2，合并对象属性

    合并的时候如果具有相同属性，会覆盖赋值。

    var ob1 = { a: 1 };
    var ob2 = { b: 2 };
    var o3 = { c: 3 };
    var obj66 = Object.assign({}, ob1, ob2, o3);
    console.log(obj66); //{a:1,b:2,c:3};

    // 在对象上面合并 数据
    // let site = Object.assign({}, this.obj, { a: 1, e: 2 })

 

3，动态给一个对象，添加数组里的内容

    let objStr = {};
    let arrImg = [11, 22, 33];
    for (let i = 0; i < arrImg.length; i++) {
      objStr["name" + i] = arrImg[i];
    }
    console.log(objStr);

 

4，对象合并 数组内容，js对象添加数组

    const dataValue = { aa: 11, bb: 1 };
    const arrImg2 = ["img1", "img2", ""];
    let obj2;
    const setimg = () => {
      //   数组的解构赋值
      const [annexUrlOne, annexUrlTwo, annexUrlThree] = arrImg2 || [];
      const obj1 = { annexUrlOne: "", annexUrlTwo: "", annexUrlThree: "" };
      obj1.annexUrlOne = annexUrlOne;
      obj1.annexUrlTwo = annexUrlTwo;
      obj1.annexUrlThree = annexUrlThree;
      obj2 = Object.assign({}, dataValue, obj1);
    };
    setimg();
    console.log(obj2);

 react 中对象合并数组

// 对象 添加数组 合成一个新对象
const [dataValue, setDataValue] = useState({one:001, two:002});
const [arrImg, setArrImg] = useState([11,222,33]);
const [annexUrlOne, annexUrlTwo, annexUrlThree] = arrImg || [];
const params = {
  ...dataValue,
  annexUrlOne,
  annexUrlTwo,
  annexUrlThree,
  headUrl: headImage
};

 

5，对象合并 数组

    // js Object.assign 添加数组
    const arr = [1,2,3]
    let obj00 = {}
    let b = Object.assign({}, obj00, arr)
    console.log(b)

 

ES6 对象的解构赋值

    let { foo , bar } = { foo: "aaa", bar: "bbb" };
    // foo = "aaa"
    // bar = "bbb"

    // 从函数返回多个值，取值
    function example () {
        return {foo2: 1, bar2: 2}
    }
    let { foo2, bar2 } = example()

    // 提取后台返回的JSON数据
    // 解构赋值对提取JSON对象中的数据，尤其有用。
    let jsonDate = { id:42, status:'OK', data:[86, 87] }
    let {id, status, data:number } = jsonDate;
    console.log(id, status, number);
    // 42, "OK", [86, 87]

参考：https://blog.csdn.net/qq_36838191/article/details/80856656

 

参考：

http://jsrun.net/aZaKp/edit

http://jsrun.net/KggKp/edit

https://zhuanlan.zhihu.com/p/112519943

https://www.cnblogs.com/lhl66/p/9505256.html

你一定要努力，但千万别着急

https://www.jianshu.com/p/4dca882392b9

https://www.jianshu.com/p/3bfb8a1ec7ef