Do you know?

1. hasOwnProperty() filter out properties that comes through prototype chain

2. HTMLColletion objects are live queries on DOM. and DOM operations are normally expensive

3. i+=1 is better than i++;

4. Javascript implicitly typecast variables while comparing, to avoid it use === or !== instead of == or !=

5. eval() is evil. Just avoid it

6. Passing strings to setInterval(),setTimeout() and Function() is more or less like eval()