Pack 5 Real-world formats

Real-world formats is for players who know the basics and want to check text the way an app does. Every board mixes valid values with near-misses that a real validator must reject, such as 24:00 for a clock time or 256 for a piece of an IP address.

You check 24-hour times, IPv4 octets from 0 to 255 without leading zeros, URL slugs like my-post, semantic versions like 2.11.3, double-quoted strings and variable names like _private. Number ranges are the hard part. A regex has no idea what 255 means, so you spell the range out digit by digit with alternation.

Every level also has hidden checks: words you don’t see. Passing the words on screen solves a level; passing the hidden checks too ranks it.

For more of the same, Format validators covers the inputs web forms ask for. The Field work track shows these skills on logs, receipts and emails.