Javascript trap window global object_javascript skills

Ff and ie6 run the same results. It doesn't seem to be a bug. Why? Note: When the object method accesses the attributes of its object | required | use this. (unlike java). function Test (){
This. name = 'test ';
Var name = 2;
This. show = function (){
Alert (name );
Alert (this. name); // display name
}
}
Var test = new Test (); // create an object through the constructor
Test. show (); // output 2 and 'test', indicating that this must be added when the object method accesses its attributes.

Function Test2 (){
This. name = 'test2 ';
This. show = function (){
Alert (name );
Alert (this. name );
}
}
Test (); // directly call Test ();
Var test2 = new Test2 ();
Test2.show (); // output Test and Test2. It's strange. What is the value of name, and how can it be 'test' or a bug?
Alert (name );
Window. show (); // output 2, test; how can we use the show function? Is it a bug?

// Output 2, Test; Test, Test2; Test; 2, Test in sequence

// Ff and ie6 run the same results. It does not seem to be a bug. Why?
// Note: When an object method accesses its object attributes | required | use this. (unlike java ).
// The entire page is | window | object by default. The defined function is the window object method by default.
// When a function is directly called, it is equivalent to calling a method through window., then this inside the method is naturally \
// Window object. this. name = 'test' indicates that an attribute is added to the window object.
// When the name is not defined in the local scope of the method and alert (name) is called, it is equivalent to calling alert (window. name );
/* Ah, the code is messy. This looks like a very serious trap !! */