rustHow to use named capture groups in Rust regex?

Named capture groups in Rust regex are used to capture a part of a string and assign it a name. This allows for easier access to the captured part of the string.

Example code

let re = Regex::new(r"(?P<year>\d{4})-(?P<month>\d{2})-(?P<day>\d{2})").unwrap();
let caps = re.captures("2020-04-30").unwrap();
println!("Year: {}", caps.name("year").unwrap());
println!("Month: {}", caps.name("month").unwrap());
println!("Day: {}", caps.name("day").unwrap());

Output example

Year: 2020
Month: 04
Day: 30

Code explanation

• let re = Regex::new(r"(?P<year>\d{4})-(?P<month>\d{2})-(?P<day>\d{2})").unwrap();: This line creates a new Regex object with the pattern (?P<year>\d{4})-(?P<month>\d{2})-(?P<day>\d{2}). The ?P<year> and ?P<month> and ?P<day> are the named capture groups.
• let caps = re.captures("2020-04-30").unwrap();: This line captures the string 2020-04-30 using the Regex object re.
• println!("Year: {}", caps.name("year").unwrap());: This line prints the value of the capture group year which is 2020.

Helpful links

• Rust Regex Documentation
• Named Capture Groups in Rust Regex

Edit this code on GitHub