Install Yosemite to a designated partition

[BigMac87]

In short, I would like to install OSX Yosemite to a designated partition while keeping my Windows & Linux systems intact. The only video I saw on installation was with a wiped hard drive, but I'd prefer not to do that. (https://www.youtube.com/watch?v=VSYkUkngdb4 about 3:30 is where he wipes and partitions the hard drive)
If I keep a designated unallocated, unformatted space will the Yosemite installer be able to format that section for OSX?
P.S. Obviously I'm a bit new to this
Thanks very much in advance for your help!