how to create a constructor function in javascript code example

Example 1: metodo constructor javascript

//CREAR UNA CLASE
class miClase {
    constructor(primero, segundo) {
        this.uno = primero;
        this.dos = segundo;
        this.tres = "Hola a todos";
    };
    miMetodoUno() {
        return this.dos;
    }
    miMetodoDos(parametroUno, parametroDos) {
        console.log(
            "El parametro UNO es: " + parametroUno +
            "<br>El parametro DOS es: " + parametroDos
        )
    }
}
//CREAR UN OBJETO - instanciar
var objetoUno = new miClase("Antonio", 56);
//RECUPERAR DATOS
objetoUno.miMetodoDos("Manuel", 44);

Example 2: javascript constructor function

function ClassMates(name,age){
  this.name=name;
  this.age=age;
  this.displayInfo=function(){
    return this.name + "is " + this.age + "year's old!";
  }
}

let classmate1 = new ClassMates("Mike Will", 15);
classmate.displayInfo(); // "Mike Will is 15 year's old!"

Example 3: js constructor object

function Car(make, model, year) {
  this.make = make;
  this.model = model;
  this.year = year;
}

var car1 = new Car('Eagle', 'Talon TSi', 1993);

console.log(car1.make);
// expected output: "Eagle"

Example 4: javascript constructor object

function Person(first, last, age, eye) {
  this.firstName = first;
  this.lastName = last;
  this.age = age;
  this.eyeColor = eye;
}

Example 5: JavaScript constructor function

// constructor function
function Person () {
    this.name = 'John',
    this.age = 23
}

// create an object
const person = new Person();