In general, there won't be any particular type of monitor which you would need. Code is just a text file containing lines of text. You don't need anything special for Notepad, do you? Like the other answer said, ergonomics is probably more important. read more
If you want to choose the best monitor for writing code, you need to know a few things. First and foremost, your new monitor setup should be nice to your eyes. This depends on different things like screen size, resolution, display panel and etc. read more
You can get a great 27-inch monitor for $450, while 2560×1600 30-inch monitors can be hundreds of dollars more expensive (and heavier and possibly too big for your desk space). read more