JavaScript/Inheritance

instanceof operator

The instanceof operator determines if an object was instantiated as a child of another object, returning true if this was the case.

Inheritance by Prototypes

The prototype of an object can be used to create fields and methods for an object. This prototype can be used for inheritance by assigning a new instance of the superclass to the prototype.

function CoinObject()
{
    this.value = 0; 
    this.diameter = 1;
}
 
function Penny()
{
    this.value=1;
}
Penny.prototype = new CoinObject();
 
function Nickel()
{
    this.value=5;
}
Nickel.prototype = new CoinObject();

Inheritance by functions

function CoinObject()
{
    this.value = 0; 
    this.diameter = 1;
}