how to create a constructor in javascript

1class Person {
2  constructor(name) {
3    this.name = name;
4  }
5  introduce() {
6    console.log(`Hello, my name is ${this.name}`);
7  }
8}

1function Person(first, last, age, eye) {
2  this.firstName = first;
3  this.lastName = last;
4  this.age = age;
5  this.eyeColor = eye;
6}

1function Car(make, model, year) {
2  this.make = make;
3  this.model = model;
4  this.year = year;
5}
6
7var car1 = new Car('Eagle', 'Talon TSi', 1993);
8
9console.log(car1.make);
10// expected output: "Eagle"

1function Bird() {
2  this.name = "Albert";
3  this.color  = "blue";
4  this.numLegs = 2;
5}
6
7let blueBird = new Bird();
8

1function Tree(name) {
2  this.name = name
3}
4
5let theTree = new Tree('Redwood')
6console.log('theTree.constructor is ' + theTree.constructor)
7

1// constructor function
2function Person () {
3    this.name = 'John',
4    this.age = 23
5}
6
7// create an object
8const person = new Person();