Regular: Expressions Cookbook, Second Edition

of symbols you've found in code.

Elias closed the Regular Expressions Cookbook . He patted the cover, where the illustrated bird seemed to stare back at him with knowing eyes.

"A trap," Elias said. "We’re looking for a specific sequence: four or more digits preceded by an ID tag, followed by a space, but—and here’s the trick—only if that same line contains a non-ASCII character hiding in the buffer." Regular Expressions Cookbook, Second Edition

: Stripping unwanted whitespace or hidden characters from text.

: Ensuring emails, phone numbers, and passwords meet criteria. of symbols you've found in code

He opened a terminal window. The code was a blur of hexadecimal nonsense. He looked back at the book, specifically a section on "Lookarounds and Backreferences." With the precision of a watchmaker, he began to type. /(?<=ID:)\d{4,}(?=\s)(?=.*[^\x00-\x7F])/g Sarah watched the screen. "What is that?"

Elias didn’t look up from his monitor. He simply reached for the Cookbook . He flipped through the pages, his fingers moving past chapters on "Validation and Formatting" and "Numbers and Dates." He was looking for something more dangerous. He was looking for Chapter 8: "Markup and Data Formats." "A trap," Elias said

to test and visualize your expressions in real-time. Which part of the Regex world