The result is the number of a buffer, as it is displayed by the ":ls" command. For the use of {expr}, see |bufname()| above. If the buffer doesn't exist, -1 is returned. Or, if the {create} argument is present and not zero, a new, unlisted, buffer is created and its number is returned. bufnr("$") is the last buffer: :let last_buffer = bufnr("$") The result is a Number, which is the highest buffer number of existing buffers. Note that not all buffers with a smaller number necessarily exist, because ":bwipeout" may have removed them. Use bufexists() to test for the existence of a buffer.