Prototypes

    /******************************************************
    // [ toString, valueOf, isPrototypeOf hasOwnProperty……]
    // obj ==> obj.prototype (Object prototype) ==> null 
    Object prototypes in JavaScript
    ******************************************************/ 
    let obj1 = {
        prop1: ( ) => { console.log('prop1') }
    } ;
    let obj2 = {
        prop2: ( ) => { console.log('prop2') }
    } ;
    
    obj.prop1( );	    // returns ‘prop1’
    obj.prop2( );	    // will check the prototype chain for ‘prop2’ otherwise will return an error
    obj.toString( );	// every object in JavaScript has a prototype object. That object has the toString Method 
    Object.setPrototypeOf(obj2, obj1);	// set the prototype of obj2 to be obj1
    obj2.prop2( );
    obj2.prop1( );
     
    for (let prop in obj2) {
        console.log(prop);	// logs out each property in obj2
    }
    
    Object.getPrototypeOf(obj2)	            // returns the prototype of obj2, which is obj1. Same as just writing obj1 
    Object.getPrototypeOf(obj2).prop1( )	// returns ‘prop1’
    Object.getOwnPropertyNames(obj2);	    // returns all properties in just obj2 
    Object.getOwnPropertyNames(Object.PrototypeOf(obj1));	// returns all properties of default object 
    Object.create( )	// can create custom properties, with property descriptors
    Object.assign( )	// can just list of the properties