Regex Game

task desc: "Now, we want to intercept the letter A at any position and try to append the number after it." in-game testcases & expected outputs (counting occurrence of such pattern): A33 -> 1 33 -> 0 33A -> 1 3A3 -> 1 A -> 1 my answer (treated as incorrect in the game, despite outputting the same number): /A/ game's solution: /A\d?/ that's totally a misleading UI/UX, since the game did not really asks you to "count" the occurrence. instead, it asks you to match what explained in the task description. for example, the first test "A33" expect you to highlight "A3", and the last test "A" expect you to highlight "A"...... so why showing us with the number of occurrence, when you can just straightly showing the match themselves??? note that this is only the 4th level in the game. also lesson + task description (for all of the levels in this game) are super confusing with bad UI/UX on top hard pass for everyone regardless of regex experience edit note: 2026-01-18: thx @Gweltaz for clarification on the level /A\d?/

I’ve been trying to learn regex properly for years. It never “stuck” well enough for me to write anything beyond trivial patterns. I hoped this game would finally change that. After just a few minutes in the first couple of modules, I’m convinced it won’t. The developers may know regular expressions, but the material suggests they don’t know how to teach them. The UI is unintuitive, and the explanations contain mistakes and oversights. This is from the very first lesson (unedited): \d = 1 decimal digit \d\d = 2 consecutive decimal digits \d\d\d = 3 digits... \d\d\d\d = 4 digits... \d\d\d\d\d = 5 digits... \d\d\d\d\d... = 100 digits... This is baffling. The use of ... is inconsistent and misleading. Appending ... after the lines for 3, 4, and 5 digits appears to suggest “and so on” (???) but then ... is shown as if it were part of the actual pattern in the final line. In regex, a dot . matches any single character, so \d\d\d\d\d... does not mean “100 digits.” It matches exactly five digits followed by three arbitrary characters. If the lesson meant “100 digits,” it should have used a quantifier: \d{100}. If it meant “three digits,” use \d{3}. If it meant “three or more,” use \d{3…

How did they translated into other languages? Seems like they used Google translate or a lower quality translator, at least for Spanish. The explanations fall short and are very confusing. I had to use external documentations to understand things on the second and third lesson. The UI is not intuitive and looks doesn't seem polished. I'll try it again after some updates and make my comments here.

Fun way to learn regex.

1v1 me regex

Thank you for great Regex trainer!