JavaScript class inheritance

<SCRIPT type = "text/JavaScript">
// Base class function baseclass () {alert ('baseclass ');}
Baseclass. Prototype. Hello = function () {alert ("baseclass. Hello")} // subclass function subclass () {alert ("subclass ")
// Override the parent class method this. Hello = function (){
Baseclass. prototype. hello. call (this); // call the method of the parent class alert ("subclass hello") ;}// set the base class subclass of the subclass. prototype = new baseclass ();
// Set the subclass constructor of the subclass. prototype. constructor = subclass; window. onload = function () {var subclass = new subclass (); subclass. hello (); // calls the hello of the subclass. If the hello of the subclass is removed, the hello of the parent class is called by default.} </SCRIPT>