String.IsNullOrEmpty in JavaScript

Starting with:

return (!value || value == undefined || value == "" || value.length == 0);

Looking at the last condition, if value == "", it's length MUST be 0. Therefore drop it:

return (!value || value == undefined || value == "");

But wait! In JS, an empty string is false. Therefore, drop value == "":

return (!value || value == undefined);

And !undefined is true, so that check isn't needed. So we have:

return (!value);

And we don't need parentheses:

return !value

Q.E.D.


http://codereview.stackexchange.com/questions/5572/string-isnullorempty-in-javascript

[jQuery]add dynamic rows

Ref:
http://stackoverflow.com/questions/2145012/adding-rows-dynamically-with-jquery

http://ssiddique.info/different-ways-to-add-row-to-a-table-using-jquery.html

http://stackoverflow.com/questions/16183231/jquery-append-and-remove-dynamic-table-row