I am currently transforming from Java to Javascript, and it's a bit hard for me to figure out how to extend objects the way I want it to do.
I've seen several people on the internet use a method called extend on object. The code will look like this:
var Person = {
name : 'Blank',
age : 22
}
var Robot = Person.extend({
name : 'Robo',
age : 4
)}
var robot = new Robot();
alert(robot.name); //Should return 'Robo'
Does anyone know how to make this work? I've heard that you need to write
Object.prototype.extend = function(...);
But I don't know how to make this system work. If it is not possible, please show me another alternative that extends an object.
17 Answers
You want to 'inherit' from Person's prototype object:
var Person = function (name) {
this.name = name;
this.type = 'human';
};
Person.prototype.info = function () {
console.log("Name:", this.name, "Type:", this.type);
};
var Robot = function (name) {
Person.apply(this, arguments);
this.type = 'robot';
};
Robot.prototype = Person.prototype; // Set prototype to Person's
Robot.prototype.constructor = Robot; // Set constructor back to Robot
person = new Person("Bob");
robot = new Robot("Boutros");
person.info();
// Name: Bob Type: human
robot.info();
// Name: Boutros Type: robot
Simpler "prose-like" syntax with Object.create()
And the true prototypial nature of Javascript
*This example is updated for ES6 classes and TypeScript.
Firstly, Javascript is a prototypal language, not class-based. Its true nature is expressed in the prototypial form below, which you may come to see that is very simple, prose-like, yet powerful.
TLDR;
