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

/
/
mg

Test String

Code Generator

Language

Generated Code

import java.util.regex.Matcher; import java.util.regex.Pattern; public class Example { public static void main(String[] args) { final String regex = "^(?<name>.*)time:\\s*\\[(?<low>\\d+\\.?\\d*)\\s(?:\\w{1,2})\\s(?<value>\\d+\\.?\\d*)\\s(?<unit>\\w{1,2})\\s(?<high>\\d+\\.?\\d*).*$"; final String string = "Symbol Creation time: [567.19 us 572.98 us 580.80 us]\n" + "Found 17 outliers among 100 measurements (17.00%)\n" + " 4 (4.00%) high mild\n" + " 13 (13.00%) high severe\n\n" + " Running target/release/deps/fib-9ff430dbccaab995\n" + "Benchmarking fibonacci (Execution): Warming up for 3.0000 s\n" + "fibonacci (Execution) time: [5.4756 ms 5.5354 ms 5.6049 ms]\n" + "Found 13 outliers among 100 measurements (13.00%)\n" + " 3 (3.00%) high mild\n" + " 10 (10.00%) high severe\n\n" + " Running target/release/deps/string-21e60149b4b73866\n" + "Hello World (Execution) time: [518.17 us 519.92 us 521.89 us]\n" + "Found 12 outliers among 100 measurements (12.00%)\n" + " 7 (7.00%) high mild\n" + " 5 (5.00%) high severe\n" + " \n" + "Hello World (Lexer) time: [1.8861 us 1.9440 us 2.0071 us]\n" + " change: [+13.420% +15.685% +17.802%] (p = 0.00 < 0.05)\n" + " Performance has regressed.\n" + "Found 2 outliers among 100 measurements (2.00%)\n" + " 1 (1.00%) high mild\n" + " 1 (1.00%) high severe\n\n"; final Pattern pattern = Pattern.compile(regex, Pattern.MULTILINE); final Matcher matcher = pattern.matcher(string); while (matcher.find()) { System.out.println("Full match: " + matcher.group(0)); for (int i = 1; i <= matcher.groupCount(); i++) { System.out.println("Group " + i + ": " + matcher.group(i)); } } } }

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 Java, please visit: https://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html