How can i write a function to do some specific operation on the line

what I want is to make a function to do this: class="btn btn-lg" -> class={`btn btn-lg`} basically replace the first `"` " -> {` and then second `"` " -> `} edit: fixed formatting

Do a macro for it :)

Unless this is something you're going to need long-term, I'd use a keyboard macro or a regexp search+replace. If you really want a function, give more details. Is this only for `class` attributes? What position (or range of positions) can point be at when you call the function? What if there are multiple such attributes on the line?

this should work on only current line, regardless of class or any other attribute.

how can i save a macro , so that i can use it over and over ?

https://www.emacswiki.org/emacs/KeyboardMacrosTricks#h5o-5