rustHow to use regex lookahead in Rust?

Regex lookahead is a powerful tool for pattern matching in Rust. It allows you to match patterns that are not necessarily adjacent to each other.

Example code

let re = Regex::new(r"(?=.*\d)(?=.*[a-z])(?=.*[A-Z]).{8,}").unwrap();
let text = "MyPassword123";
assert!(re.is_match(text));

Output example

true

Code explanation

• Regex::new: creates a new Regex object from a given pattern string
• (?=.*\d): lookahead assertion that checks for at least one digit
• (?=.*[a-z]): lookahead assertion that checks for at least one lowercase letter
• (?=.*[A-Z]): lookahead assertion that checks for at least one uppercase letter
• .{8,}: checks for at least 8 characters
• is_match: checks if the given text matches the pattern

Helpful links

• Regex Lookahead Assertions
• Regex Documentation

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