Regular Expressions 101

Save & Share

Flavor

  • PCRE2 (PHP >=7.3)
  • PCRE (PHP <7.3)
  • ECMAScript (JavaScript)
  • Python
  • Golang
  • Java 8
  • .NET 7.0 (C#)
  • Rust
  • Regex Flavor Guide

Function

  • Match
  • Substitution
  • List
  • Unit Tests

Tools

Sponsors
There are currently no sponsors. Become a sponsor today!
An explanation of your regex will be automatically generated as you type.
Detailed match information will be displayed here automatically.
  • All Tokens
  • Common Tokens
  • General Tokens
  • Anchors
  • Meta Sequences
  • Quantifiers
  • Group Constructs
  • Character Classes
  • Flags/Modifiers
  • Substitution
  • A single character of: a, b or c
    [abc]
  • A character except: a, b or c
    [^abc]
  • A character in the range: a-z
    [a-z]
  • A character not in the range: a-z
    [^a-z]
  • A character in the range: a-z or A-Z
    [a-zA-Z]
  • Any single character
    .
  • Alternate - match either a or b
    a|b
  • Any whitespace character
    \s
  • Any non-whitespace character
    \S
  • Any digit
    \d
  • Any non-digit
    \D
  • Any word character
    \w
  • Any non-word character
    \W
  • Non-capturing group
    (?:...)
  • Capturing group
    (...)
  • Zero or one of a
    a?
  • Zero or more of a
    a*
  • One or more of a
    a+
  • Exactly 3 of a
    a{3}
  • 3 or more of a
    a{3,}
  • Between 3 and 6 of a
    a{3,6}
  • Start of string
    ^
  • End of string
    $
  • A word boundary
    \b
  • Non-word boundary
    \B

Regular Expression

/
/

Test String

Code Generator

Generated Code

// include the latest version of the regex crate in your Cargo.toml extern crate regex; use regex::Regex; fn main() { let regex = Regex::new(r"(?<=\ id\ \|.)(([a-zA-Z0-9_]{8})-([a-zA-Z0-9_]{4})-([a-zA-Z0-9_]{4})-([a-zA-Z0-9_]{4})-([a-zA-Z0-9_]{12}))").unwrap(); let string = "Created a new subnet: +-------------------+------------------------------------------------+ | Field | Value | +-------------------+------------------------------------------------+ | allocation_pools | {\"start\": \"10.42.42.2\", \"end\": \"10.42.42.254\"} | | cidr | 10.42.42.0/24 | | dns_nameservers | | | enable_dhcp | True | | gateway_ip | 10.42.42.1 | | host_routes | | | id | 3eded702-2909-4515-bf74-7c7c2c7c96e3 | | ip_version | 4 | | ipv6_address_mode | | | ipv6_ra_mode | | | name | Atelier | | network_id | 5d15b14c-1d39-48d5-8f48-0dfd68c98d47 | | tenant_id | d3c17d0e8bd742ed939794a98991886f | +-------------------+------------------------------------------------+ "; // result will be a tuple containing the start and end indices for the first match in the string let result = regex.captures(string); let (start, end) = match result { Some((s, e)) => (s, e), None => { // ... } }; println!("{}", &string[start, end]); }

Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Rust, please visit: https://docs.rs/regex/latest/regex/