A Practical Regex Debugging Checklist

Regex is dense — debug systematically.

Checklist

1. Anchor intent — Should ^ / $ constrain the whole string or a line?
2. Greedy vs lazy — .* swallows too much; try .*? or negated classes.
3. Unicode — Use explicit flags; beware combining marks vs graphemes.
4. Escape meta characters — Dots, parentheses, and brackets are special unless escaped.

Test safely in the Regex Tester and read What Is Regex? for pattern building blocks.