Websites to learn Regex

Created: 2022-07-24
Tags: #fleeting

1. Use https://regexr.com/. You can paste an expression at the top, mouse over each highlighted section, and it will explain what that part does. It's a great way to decipher hieroglyphics into something you can start to understand.
   

2. Complete https://regexone.com/. It's a great interactive introduction to regular expressions that should fill any gaps in your knowledge. You have to fill in the regex that satisfies the named matches.

   2. Once you're done with tutorial. Do some practice problems
      https://regexone.com/problem/matching_decimal_numbers

3. Complete https://regexcrossword.com/. It's a “reverse regex” crossword web game where you have to type the string that satisfies the expressions in all of the row and column headers. (See https://regexcrossword.com/howtoplay.)

4. Look at common regex patterns and try to understand them. Paste some from https://projects.lukehaas.me/regexhub/ into regexr.com and hover over each group in the regex to help figure out anything you're not familiar with. Start with the shortest examples that you don't yet understand.