I'm editing a source file in Vim, and in the middle of it I want to search for a tag (to understand some variable/class/method etc.), and I click Ctrl+] to look for the tag, and if the tag is supposed to be in a different file, it doesn't allow me to move away from the current file because it is being edited - it displays the usual Vim error - "E37: No write since last change (add ! to override)"
The workaround I have is to save the file first and re-open it and then look for the tag.
Is there a way to search the tags without having to save and reopen the file.
You can put the following line in your vimrc to allow Vim to edit another buffer without having to write the current one:
set hidden
See :help 'hidden'.
If you don't want to set that option, the alternative would be to use <C-w>], which opens the tag in a new window. See :help ctrl-w_].
Note that, as pointed out in a comment, you don't have to write and quit the current buffer in order to jump to a tag: writing it is enough.