Use of classes in typescript

/*
*  Base class 
* */
class Base{
    constructor(obj=null) {
        if (obj){
            console.log(' Subclass call , Base class constructor ',obj.a,obj.b);
        }else{
            console.log(' Base class constructor ');
        }

    }
    toString(obj){
        let [a,b]=[obj.a,obj.b];
        console.log(' Subclass call :toString()===>',a,b);
    }
}

/*
*  Derived class , Inherited from Base
* */
class Framework extends Base{
    constructor({a=0,b=0}={}) {
        super({a,b});// Pass parameters to the base class 
        super.toString({a,b});// Call the base class function 
    }
    // Public method implementation , By default, all methods of the class are public 
    getParentName(){

    }

    // Private method implementation of class 
    _getParentName(){

    }
}

let base = new Base();// Instantiate base class 
let framework = new Framework({a:8,b:9});// Instantiate derived classes 
// Class instances are objects , Classes are functions 
console.log(' Data type of class object :',typeof base,typeof framework,' The data type of the class ',typeof Base,typeof Framework);
console.log(' Class prototype object construction :',Framework.prototype.constructor,' Class construction :',Framework.constructor);
console.log(' Class prototype Of constructor Point to the class name :',Framework.prototype.constructor===Framework);// Class prototype Of constructor Point to the class name 
console.log(' Class name :',Framework.name);
console.log(framework.constructor===Framework.prototype.constructor);

// Add methods to the class through the class prototype object 
Base.prototype.Add = function (x,y) {
    return x+y;
}
console.log(' Call the method added to the base class prototype object :',base.Add(1,2));// Call the method added to the base class prototype object 
console.log(' The derived class calls the method of the base class prototype object :',framework.Add(5,6));// The derived class calls the method of the base class prototype object 

// @ts-ignore
Base.prototype.test =()=> {
  console.log('test func');
};

console.log(Object.getOwnPropertyNames(Base.prototype));// Take all method names of the class 

// Use Object.assign Add methods to the class 
Object.assign(Base.prototype, {
    M1() {
        console.log('M1');
    },
    M2() {
        console.log('M2');
    },
    M3() {
        console.log('M3');
    }
});
// Call the added method 
base.M1();
framework.M2();
framework.M3();

// notes :  All methods defined inside the class are non enumerable 
console.log(Object.keys(Base.prototype));//constructor,toString Both methods are defined inside the class , therefore Object.keys Can't enumerate 

// Use variable names to define class methods 
let method = 'Done';
Object.assign( Base.prototype,{[method](){
    console.log(' Functions defined by variable names ');
}});

console.log(Object.keys(Base.prototype));
base.Done();// Call by method name 
Reflect.get(base,method)();// Use reflection to call through variable names 
framework.Done();
console.log(Object.getOwnPropertyNames(Framework.prototype));
console.log(' Take the inheritance object of the current class ',Object.getPrototypeOf(framework));
console.log(' Take all methods of the inherited object of the current class ',Object.getPrototypeOf( Object.getPrototypeOf(framework)));
// Get the base class according to the subclass , And call the base class method 
let p = Object.getPrototypeOf( Object.getPrototypeOf(framework))
p.Done();
console.log(Object.getOwnPropertyNames(p));
console.log(Reflect.ownKeys(p));
Reflect.get(p,method)();

console.log('base Object prototype ',base.__proto__,'framework Object prototype :',framework.__proto__);


// Declare classes in the form of expressions 
const ExpClass = class Exp {// here Exp Is the alias of the class , Scope is limited to the internal definition of the class 
    constructor() {
        console.log(' Print the class name when constructing :',Exp.name);
    }
    getClassName(){
        console.log(' call getClassName Print the name of the class :');
        return Exp.name;
    }
}

let exp = new ExpClass();
console.log(exp.getClassName());

// Execute class immediately 
let execClass = new class{
    constructor() {
        console.log(' Execute class immediately ');
    }
}();
// Immediate execution class with parameters 
let execClassWithParam = new class{
    constructor(param) {
        console.log(' Execute class immediately , Parameters :',param);
    }
}('RemoteDev');
// notes :  Class does not have variable Promotion , You must declare before instantiating