Regular Expressions 101

Save & Share

  • Regex Version: ver. 81
  • Update Regex
    ctrl+⇧+s
  • Save new Regex
    ctrl+s
  • Add to Community Library

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
No Match

/
/
g

Test String

Code Generator

Language

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"UNIT OPENER").unwrap(); let string = "NGSS Lesson Outline with Manuscript HISTORY Version Stage Writer/Reviewer Notes Date 1 Dev Prep1 Maryum Mohsin Script build prep 9-9-16 Contents HISTORY 1 UNIT OVERVIEW 1 UNIT OPENER 1 UNIT PROJECT 1 VOCABULARY 2 UNIT OVERVIEW CODE TK Grade Level 2 Unit Title Earth’s Surface UNIT OPENER Page Title Unit Opener Section Part Content UnitOpener_1 Habitat Pattern: STATIC – Unit Opener SCREEN VO: Unit 4 Earth’s Su rface [RCE Head]: Unit 4 Earth’s Surface Media: Splash: Spec ID# 883V Text [I mage Caption]: UNIT PROJECT Page Title Unit 4 Project Section Part Content UnitProject_1 Habitat Pattern: STATIC – Intro Unit Project SCREEN VO: Why does n’t an ocean freeze completely? Investigate to find out. [RCE Head]: Unit 4 Pro ject Text [Head]: Explore Ocean Water Text [Directional Text]: Why does an oce an not freeze completely? Investigate to find out. Media: Spec ID# 884P Text [I mage Caption]: [icon w/ link to downloadable worksheet] VOCABULARY Page Title Unit Review Section Part Content UnitVocabulary_1 Habitat Pattern: INTERACTIVE – TR_Main [RCE head]: Unit 4 Voca bulary SCREEN VO: Unit 4 Vocabulary Each card shows a word you will use in thi s unit. Choose a card to find out more about the word. Text [Directional Text]: Each card shows a word you will use in this unit. Choose a card to find out mo re about the word. Media and Options: Voc1: mapVoc2: map titleVoc3: map keyVoc4 : compass rose Voc1: Text [label]: map Image1: Spec ID# 900M [simple town map p/u 463M]] Text VO: map a drawing or a model of a place Voc2: Text [label]: map title Image2: S pec ID# 901M [close up of map title p/u 464M] Text VO: map title part of a map t hat tells what the map shows Voc3: Text [label]: map key Image3: Spec ID# 902M [close up of map key p/u 464M] Text VO: map key part of a map that shows what t he map colors and symbols mean Voc4: Text [label]: compass rose Image4: Spec ID # 903M [close up of compass rose p/u 464M] Text VO: compass rose part of a map t hat shows the directions north, south, east, and west "; // result will be an iterator over tuples containing the start and end indices for each match in the string let result = regex.captures_iter(string); for mat in result { println!("{:?}", mat); } }

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/