Characters have a defined way of writing the strokes, so you look them up by number of strokes and radical. ("Radical" being, usually, the bit on the left or the top)
You can see a web-based example at [2]. Click on the "Radicals" button in the upper right. You'll see a list of radicals (sorted by stroke order), and clicking/unclicking on them will cause the list of kanji below to change.
Kanji are composed from a much smaller set of radicals, so you look it up by the radicals that compose it. Some dictionaries also divide characters up by stroke count. For the past 15+ years, electronic dictionaries with handwriting recognition have been popular, and now you can just use your phone keyboard.
In practice, sometimes you can also kind of guess at the pronunciation (since characters with the same main radical often have a similar pronunciation) and see what autocomplete lists; maybe that's less true outside of the joyo kanji, though.
Of course they do. In fact, there are two main types of Chinese dictionaries: phonetic dictionaries organized by pronunciation and character dictionaries organized by radical.
Thanks for the reply, my question was intented to be rhetorical but my writing style wasn't the best. I was just trying to get JohnBooty to do a quick google search for Kanji/Hanzi dictionaries, after all how else could the east have developed such a sophisicated literary tradition without dictionaries.
You can see a web-based example at [2]. Click on the "Radicals" button in the upper right. You'll see a list of radicals (sorted by stroke order), and clicking/unclicking on them will cause the list of kanji below to change.
[0] https://www.tofugu.com/japanese/kanji-stroke-order/ [1] https://en.wikipedia.org/wiki/List_of_kanji_by_stroke_count [2] https://tangorin.com/kanji