Will Yongnuo YN-560 IV for nikon work with canon?

Will Yongnuo YN-560 IV for nikon work with canon? - 1

In a limited way perhaps. Any auto modes won't because Canon and Nikon cameras will have different ways of talking to the camera.

No, it needs to be specific for the camera. The configuration of the contact pins is different for Canon and Nikon.

Most probably in Auto or manual mode only with the camera in Manual mode.

Yes it will work perfectly well as long as the flash and the camera are both in manual mode.

I have used Yongnuo 560's (for Nikon) on Nikons, Canons, Olympus and Panasonic cameras with no problems (my flash & triggers tend to get passed around camera club a lot during workshops/demos).