Detailed explanation of several ways to create objects and object methods in js

 function getObj(name, age) {
  let obj = {}
  obj.name = name
  obj.age = age
  return obj
 }
 let person1 = getObj("cc", 31)

 function CreateObj(name, age) {
  this.name = name
  this.age = age
 }
 let person1 = new CreateObj("cc", 31)
 console.log(person1)
 console.log(person1.constructor === CreateObj); // true
 console.log(person1 instanceof CreateObj); // true

 function CreateObj(name, age) {
  this.name = name
  this.age = age
 }
 CreateObj('cc', 10)
 console.log(window.name) // 'cc'

person1.sayName() === person2.sayName() // false

 function sayName() {
  console.log(this.name)
 }
 function CreatePerson(name, age) {
  this.name = name
  this.age = age
  this.sayName = sayName
 }
 let person1 = new CreatePerson('joy', 31)
 person1.sayName()

 function Person() { }
 let person1 = new Person()
 console.log(person1.__proto__ === Person.prototype) // true
 console.log(Person.prototype.constructor === Person); // true

// isPrototypeOf determines whether the prototype object of the constructor is the prototype object of the instance function Person() {}
 let person1 = new Person()
 console.log(Person.prototype.isPrototypeOf(person1)); // true

// Get the prototype object of the object function Person() {}
 let person1 = new Person()
 console.log(Object.getPrototypeOf(person1) === Person.prototype);

// Set an object as the prototype object of another object let person1 = {name: "cc"}
 let person2 = {age: 32}
 Object.setPrototypeOf(person1,person2)
 console.log(person1.name, person1.age); // cc 32

// Create a new object with an object as the prototype object let person1 = {name: "cc"}
 let person2 = Object.create(person1)
 person2.age = 30
 console.log(person2.name, person2.age);

 function Person() {}
 Person.prototype.name = "cc"
 let person1 = new Person()
 console.log(person1.name) // 'cc'
 console.log(person1.hasOwnProperty("name")); // false

// Return true if found in the object itself or prototype 
function Person() {}
 Person.prototype.name = "cc"
 let person1 = new Person()
 console.log("name" in person1) // true
 console.log(person1.hasOwnProperty("name")); // false

Object.keys()
for ... in // Inherited properties are also traversed Object.getOwnPropertyNames(obj) // Lists both enumerable and non-enumerable properties, and the rest are the same as Object.keys() Object.getOwnPropertySymbols(obj) // Similar to getOwnPropertyNames, but only for symbols
Reflect.ownKeys(obj) // Same result as Object.keys()

 function Person() {}
 Person.prototype.name = "cc"
 let person = new Person()
 person.age = 21
 let sy = Symbol('sy')
 person[sy] = 'smile'
 console.log(Object.values(person)) // [ 21 ]
 console.log(Object.entries(person)) // [ [ 'age', 21 ] ]