rustHow to use regex captures in Rust?

Regex captures in Rust are used to capture substrings from a given string. Captures are stored in a Vec and can be accessed by index.

Example code

let re = Regex::new(r"(\d{4})-(\d{2})-(\d{2})").unwrap();
let text = "Today is 2020-07-30";
let captures = re.captures(text).unwrap();
println!("Year: {}", &captures[1]);
println!("Month: {}", &captures[2]);
println!("Day: {}", &captures[3]);

Output example

Year: 2020
Month: 07
Day: 30

Code explanation

• let re = Regex::new(r"(\d{4})-(\d{2})-(\d{2})").unwrap();: This line creates a new Regex object with the given pattern. The pattern (\d{4})-(\d{2})-(\d{2}) matches a date in the format YYYY-MM-DD.
• let text = "Today is 2020-07-30";: This line creates a string with the date to be matched.
• let captures = re.captures(text).unwrap();: This line captures the substrings from the given string using the Regex object.
• println!("Year: {}", &captures[1]);: This line prints the first capture, which is the year.
• println!("Month: {}", &captures[2]);: This line prints the second capture, which is the month.
• println!("Day: {}", &captures[3]);: This line prints the third capture, which is the day.

Helpful links

• Regex Captures in Rust
• Regex in Rust

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