this

I get confused about ' this ' keyword in the following codes, there are two 'this': var Foo = function(string){ this.name=string // 1st-this } Foo.prototype.get_name = function(){ return this.name // 2nd-this } var myFoo = new Foo('John') the_name=myFoo.get_name() ' the_name ' is equal to 'John', the prototype method get the name by return this.name . But can anyone explain to me the 1st- this and 2nd- this , what do they stand for? In Javascript, the value of this is dependent on the way you call the function . There are 5 ways to call a function in JS, and they all have effect on this : new

This question already has an answer here: When should I make explicit use of the `this` pointer? 12 answers I'm dealing with a large code base that uses the following construct throughout class MyClass { public: void f(int x); private: int x; }; void MyClass::f(int x) { ' ' this->x = x; ' ' } Personally, I'd always used and hence prefer the form class MyClass { public: void f(int x); private: int _x; }; void MyClass::f(int x) { ' ' _x = x; ' ' } The reasons I prefer the latter are that it is more succinct (less code = fewer potential bugs), and that I don't like having multiple variables of

What is the fundamental difference between using $(this) vs this $('.viewComments').click(function(ev){ //returns the desired value alert(this.getAttribute('id')); //Gives an error sayin function is not defined alert($(this).getAttribute('id')); //returns the desired value alert($(this).attr('id')); }); What I thought was "$(this)" will contain all functions that "this" has and more..But that doesn't seem to be the case. So what exactly is $(this)? and Hw do I know what functions are available when I'm using it? (I know I can get them through firebug. but I would like to know if there any some

this often to reference to current context. But, at some case, why we must use getBaseContext() instead of this . (It means when use this will notice error). Here is my example: Spinner spinner = (Spinner) findViewById(R.id.spinner); spinner.setAdapter(adapter); spinner.setOnItemSelectedListener(new OnItemSelectedListener() { @Override public void onItemSelected(AdapterView<?>arg0, View arg1, int arg2, long arg3){ Toast.makeText(getBaseContext(),"SELECTED", Toast.LENGTH_SHORT).show(); //this line } At above code, when I change getBaseContext() to this will receive error. Who can explain for me