JS written test question -- prototype, new, this comprehensive question

            function fn() {
			　　a = function() {
			　　　　console.log("111111")
			　　}
			　　return this
			}
			fn.a = function() {console.log("222222")}
			fn.prototype.a = function() {console.log("333333")}
			var a = function() {console.log("444444")}			
			function a() {console.log('555555')}
			fn.a()　　　   
			a()　　　　　　　
			fn().a()　
			a()　　　　 
			new fn.a()
			new fn().a()　
			new new fn().a() 
			
            // analysis 
			/*
			 Implicit promotion ：
			var a;
			function fn() {
			　　a = function() {
			　　　　console.log("111111")
			　　}
			　　return this
			};
			function a() {console.log('555555')};
			fn.a = function() {console.log("222222")};
			fn.prototype.a = function() {console.log("333333")}
			a = function() {console.log("444444")}
            
			fn.a()　// Print 222222　　   
			a()　　// Print 444444　　　　　
			fn().a()　// function fn function   Change global variables  var a=function() {console.log("111111")}
			          // return this=>window, then window.a()=> Print 111111
			a()　// Print 111111

			// priority =>() >  Some grammar |new Banded ginseng  > new No arguments | Function run 
			//new Three steps ：1. Create an empty object ,2. Run constructor internal this Point to this object ,3. The result depends on the return value => If it is reference data, return it , Otherwise, it is the object after running 　　　 
			new fn.a() // new (fn.a)() => Print 222222	           
			new fn().a()　// (new fn()).a() => Inside this by =>new Constructed empty object , Because there is no a Method , Then find the prototype , Print 333333
			new new fn().a() //new (new fn()).a() => Similar to that , Print 333333
			
			*/