Thanks for using code tags, but please also make sure that the indentation is proper. The wonky indentation in your post makes the code almost impossible to follow.
In general, jQuery applies a method to all elements that are gathered into the wrapped set by a jQuery selector. So you usually don't need to do any iteration on them if the operation to be applied is going to be the same for all of them.
If for some reason you need to treat each element individually, you can use the .each() method to invoke a callback on each element individually.
ok good sir ,my mistake for not making things clear.
Now if i click Checkbox for each row , the content for that row will be visible(Originally hidden on page load).
There are 20 checkboxes like this.
Each row has unique options based on subject . So if i use same class wont clicking a checkbox show all columns in all the rows instead of showing only columns in that particular row[which i want]?
P.S. The class name "hidden" is not a good choice because sometimes "hidden" elements are hidden, and sometimes they are displayed. So "hidden" is misleading for half the cases. I'd choose a class name such as "hide-able" or "toggle-able" to better reflect the semantics.
OK, so I gotta step away from the computer for a bit, so I'm gonna jump ahead a tad.
Assuming that the checkboxes are in the first column, and it's all of the remaining cells in that row are to be hidden when the checkbox is unchecked (if it's to be the opposite, you should be able to figure out how to change that), here's the single-line ready handler to make that happen. I'll let you dissect it to see how it works:
(ignore the newline in the middle of the statement, the forum software is doing the wrapping)
Note: no class names at all are required. (Helping to keep the markup as clean as possible.) And no iterating is needed. All the checkboxes are handled by this code.