js之Object的使用

浅拷贝：会改变原有数据
深拷贝：不会改变原有数据

• Object.assign(obj, obj1) \(\Rightarrow\) 合并两个对象为一个==（此方法为浅拷贝）==

const dealObj = (val) => {
  const obj = { name: "苏小妍", age: 13 };
  let obj1 = { sex: "女" };
  obj1 = Object.assign(obj, obj1);
  // obj=====>>> { name: '苏小妍', age: 13, sex: '女' }
  console.log("obj=====>>>", obj);
  // obj=====>>> { name: '苏小妍', age: 13, sex: '女' }
  console.log("obj1=====>>>", obj1);
};

dealObj();

这是图片

• Object.hasOwnProperty() \(\Rightarrow\) 判断对象是否包含某个 key

const hasOwnPropertyObj = (val) => {
  const obj = { name: "苏小妍", age: 13, sex: "女", job: "student" };
  console.log("hasOwnProperty=====>>>", obj.hasOwnProperty(val));
};

// true
hasOwnPropertyObj("name");
// true
hasOwnPropertyObj("sex");
// false
hasOwnPropertyObj("work");

• Object.keys() \(\Rightarrow\) 获取对象的所有 key

const objectKeys = () => {
  const obj = { name: "苏小妍", age: 13, sex: "女", job: "student" };
  // [ 'name', 'age', 'sex', 'job' ]
  console.log("objectKeys=====>>>", Object.keys(obj));
};

objectKeys();

• Object.values() \(\Rightarrow\) 获取对象的所有 value

const objectValues = () => {
  const obj = { name: "苏小妍", age: 13, sex: "女", job: "student" };
  // [ '苏小妍', 13, '女', 'student' ]
  console.log("objectValues=====>>>", Object.values(obj));
};
objectValues();

• Object.entries() \(\Rightarrow\) 获取对象的所有 key 和所有 value

const objectEntries = () => {
  const obj = { name: "苏小妍", age: 13, sex: "女", job: "student" };
  // [ 'name', '苏小妍' ],
  // ['age', 13],
  // ['sex', '女'],
  // ['job', 'student'];
  console.log("objectEntries=====>>>", Object.entries(obj));
};
objectEntries();

• 判断数据类型

const fruitsArr = [
  "Banana",
  "Cherry",
  "Peach",
  "Kiwi",
  "Leamon",
  "Watermelon",
  "Strawberry",
  "Orange",
  "Apple",
  "Mango",
  "Banana",
];

Object.prototype.toString.call(fruitsArr.join("-")); // [object String]
Object.prototype.toString.call(fruitsArr); // [object Array]