I've tried several ways but I couldn't do it.
On the next example I want the Soldier gets all properties of Person, and allowing to add more properties. How to do it correctly?
function Person(name, age) {
this.name = name;
this.age = age;
}
Person.prototype.hi = function (message) {
console.log(message + "!!!");
};
var Soldier = new(Person); // it is not the way to do it
Soldier.prototype.good_hi = function (message) {
console.log("Sir! " + message + ", sir!");
};
You don't have a Soldier constructor. You need to make that first. Then you'd apply the Person constructor to new Soldier instances.
function Person(name, age) {
this.name = name;
this.age = age;
}
Person.prototype.hi = function (message) {
console.log(message + "!!!");
};
function Soldier(name, age) {
Person.apply(this, arguments);
}
Soldier.prototype = Object.create(Person.prototype); // is better
Soldier.prototype.constructor = Soldier;
Soldier.prototype.good_hi = function (message) {
console.log("Sir! " + message + ", sir!");
};
Then use it like this:
var s = new Soldier("Bob", 23);
s.good_hi("Hello");
Soldier.prototype.constructor = Soldier; Otherwise, the constructor will be Person from the prototype object you assign.