Regular Expressions 101

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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"(^|[\s:#])0(?!0{7})\d{7}([\s:a-zA-Z]|$)").unwrap(); let string = "123 234 10 DETECT: 01234561 wordfromlistc OR wordfromlistd 01234562 OR wordfromlista01234563 OR 01234567wordfromlistb DON'T DETECT: 00000000 wordfromlist OR wordfromlist 0000000 OR 00000000wordfromlist OR wordfromlist00000000 OR DON'T DETECT: 01234567- OR -01234567 OR /01234567/, etc 01234567 00000000 00000001 1505848655000-0400 12345678 {\"context\":{\"client\":{\"clientName\":1,\"clientVersion\":\"2.20170920\"}},\"events\":[{\"eventTimeMs\":1506022852901,\"foregroundHeartbeat\":{\"firstActivityMs\":\"-1\",\"clientDocumentNonce\":\"LEPgGrs4OSu6AqVj\",\"index\":\"8\",\"lastEventDeltaMs\":\"-1\",\"trigger\":\"FOREGROUND_HEARTBEAT_TRIGGER_ON_FOREGROUND\"},\"context\":{\"lastActivityMs\":\"1791003\"}},{\"eventTimeMs\":1506022855635,\"foregroundHeartbeat\":{\"firstActivityMs\":\"2311\",\"clientDocumentNonce\":\"LEPgGrs4OSu6AqVj\",\"index\":\"9\",\"lastEventDeltaMs\":\"2733\",\"trigger\":\"FOREGROUND_HEARTBEAT_TRIGGER_ON_BACKGROUND\"},\"context\":{\"lastActivityMs\":\"861\"}}],\"requestTimeMs\":1506022865644} {\"context\":{\"client\":{\"clientName\":1,\"clientVersion\":\"2.20170920\"}},\"interactions\":[{\"attachChild\":{\"csn\":\"LBnEWZLnFcHs8wTUnKZY\",\"parentVisualElement\":{\"veType\":3854},\"visualElements\":[{\"trackingParams\":\"CAEQumkiEwiSrfTIh7fWAhVB9pwKHVSOCQsojh4=\"}]},\"eventTimeMs\":1506023726765,\"lactMs\":316},{\"attachChild\":{\"csn\":\"LBnEWZLnFcHs8wTUnKZY\",\"parentVisualElement\":{\"veType\":3854},\"visualElements\":[{\"veType\":23851,\"veCounter\":1}]},\"eventTimeMs\":1506023728252,\"lactMs\":1803},{\"attachChild\":{\"csn\":\"LBnEWZLnFcHs8wTUnKZY\",\"parentVisualElement\":{\"veType\":3854},\"visualElements\":[{\"veType\":36925,\"veCounter\":2}]},\"eventTimeMs\":1506023728253,\"lactMs\":1804},{\"attachChild\":{\"csn\":\"LBnEWZLnFcHs8wTUnKZY\",\"parentVisualElement\":{\"veType\":3854},\"visualElements\":[{\"veType\":28664,\"veCounter\":3}]},\"eventTimeMs\":1506023728253,\"lactMs\":1804},{\"attachChild\":{\"csn\":\"LBnEWZLnFcHs8wTUnKZY\",\"parentVisualElement\":{\"veType\":3854},\"visualElements\":[{\"veType\":28662,\"veCounter\":4}]},\"eventTimeMs\":1506023728253,\"lactMs\":1804},{\"attachChild\":{\"csn\":\"LBnEWZLnFcHs8wTUnKZY\",\"parentVisualElement\":{\"veType\":3854},\"visualElements\":[{\"veType\":28656,\"veCounter\":5}]},\"eventTimeMs\":1506023728253,\"lactMs\":1804},{\"attachChild\":{\"csn\":\"MhnEWc2FDdHY8gT7qJigAw\",\"parentVisualElement\":{\"veType\":3832},\"visualElements\":[{\"trackingParams\":\"CAEQumkiEwiSrfTIh7fWAhVB9pwKHVSOCQsojh4=\"}]},\"eventTimeMs\":1506023731445,\"lactMs\":560}],\"requestTimeMs\":1506023732093}"; // 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/