Why [A-z] is almost never what you want

What to check

• Probably a bug

  Character range spans more than it looks like

  `A-z` covers punctuation as well as letters, because ranges follow character codes rather than the alphabet. [A-z] for example also matches [ \ ] ^ _ and `.

  Fix: Write the ranges you mean explicitly: [A-Za-z].

• Note

  Anchors match string ends, not line ends

  Without the m flag, ^ and $ match only the very start and end of the input — not the start and end of each line. On multi-line input this is often not what was intended.

  Fix: Add the m flag if the pattern should apply per line.