For several weeks my gas oven would sometimes ignite when it was turned on and sometimes it would not without being turned off and back on several times; then finally it quit igniting altogether. I had the electronic igniter replaced, and the oven worked right for about two months, but now it has started doing the same thing again. I am thinking of replacing the igniter again before resorting to buying a new oven, but is there something else repairable that could be causing the problem? The oven is only a few years old and has had only minimal to moderate use.

You said oven, not range right? If the top AND bottom (you didn't specify which ignitor you changed) you could have a bad regulator, switch, or loose wire connection.

Here is a video to explain it.

https://www.bing.com/videos/search?q=how+gas+ovens+work&&view=detail&mid=A978B9C423B6E3DFF166A978B9C423B6E3DFF166&rvsmid=9205D196AF2B9FAD6AAD9205D196AF2B9FAD6AAD&FORM=VDQVAP