This post is a part 7 of ECMAScript 6 Complete Tutorial post series.
ECMAScript 6 introduced “class” keyword to define classes in JavaScript. Earlier to ES6, we had to use constructor function.
Here is an example code on how to define classes and then how to create objects of those class types i.e., instances of classes.
class Student
{
//constructor of the class
constructor(name, age)
{
//"this" points to the current object
this.name = name;
this._age = age;
}
//member function
getName()
{
return this.name;
}
setName(name)
{
this.name = name;
}
//getters and setters make a function accessible like a variable. They are used as wrappers around other variables.
set age(value)
{
this._age = value;
}
get age()
{
return this._age;
}
}
//class person inherits student class
class Person extends Student
{
constructor(name, age, citizen)
{
//this points to the person class
this.citizen = citizen;
//call constructor of super class. "super" is an pointer to the super class object
super(name, age);
}
getCitizen()
{
return this.citizen;
}
//overriding
getName()
{
//we are calling the super class getName function
return super.getName();
}
}
//instance of student class
var stud = new Student("Narayan", 21);
//instance of person class
var p = new Person("Narayan Prusty", 21, "India");
stud.age = 12; //executes setter
console.log(stud.age); //executes getter
{
//constructor of the class
constructor(name, age)
{
//"this" points to the current object
this.name = name;
this._age = age;
}
//member function
getName()
{
return this.name;
}
setName(name)
{
this.name = name;
}
//getters and setters make a function accessible like a variable. They are used as wrappers around other variables.
set age(value)
{
this._age = value;
}
get age()
{
return this._age;
}
}
//class person inherits student class
class Person extends Student
{
constructor(name, age, citizen)
{
//this points to the person class
this.citizen = citizen;
//call constructor of super class. "super" is an pointer to the super class object
super(name, age);
}
getCitizen()
{
return this.citizen;
}
//overriding
getName()
{
//we are calling the super class getName function
return super.getName();
}
}
//instance of student class
var stud = new Student("Narayan", 21);
//instance of person class
var p = new Person("Narayan Prusty", 21, "India");
stud.age = 12; //executes setter
console.log(stud.age); //executes getter
