The Kärcher FC 7 Cordless hard floor cleaner can partially replace the function of a vacuum cleaner, but it is not a full substitute. Here are the key points:

- The FC 7 Cordless can remove both dry and wet dirt from hard floors in a single step, eliminating the need for preliminary vacuuming.
- It uses 4 counter-rotating rollers to pick up dirt, including hair and fur, which is similar to some vacuum functions.
- However, it is specifically designed for hard floors and does not have the suction power or capabilities to handle carpets, large debris, or other surfaces that a traditional vacuum cleaner can handle.

In summary, while it can save time by combining cleaning steps for hard floors, it is not a replacement for a vacuum cleaner for all cleaning tasks.