05JS advanced methods do not have block-level scopes

<! DOCTYPE html>//the 1.js top-level scope is window        varnum = 1;        alert (window.num); //2 Method Scope        functionTest () {number2= 2;//when you declare a local variable inside a method, you need to add var or the global variable            varNUM3 = 3;//Local variables cannot be accessed outside the method            //3 No block-level scope             for(vari = 0; I < 10; i++)            {                varNUM4 = 4; } alert (NUM4); //because there is no block-level scope, the variable num4 here is a local variable of the method} test ();    alert (WINDOW.NUMBER2); </script>