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

import java.util.regex.Matcher; import java.util.regex.Pattern; public class Example { public static void main(String[] args) { final String regex = "\"([^\"]+)\":"; final String string = "{\n" + " \"activity:status\": \"BOOKED\",\n" + " \"criteria:duration\": 8,\n" + " \"criteria:tripFrom\": 1500242400,\n" + " \"criteria:tripTo\": 1500933600,\n" + " \"intent:booker\": 0.06258322237017303,\n" + " \"intent:churnRisk\": 0.3004193725304727,\n" + " \"intent:churnRiskText\": \"LOW\",\n" + " \"intent:userClass\": \"CUSTOMER\",\n" + " \"issues:acs\": 14,\n" + " \"issues:total\": 0,\n" + " \"revenue\": 2896,\n" + " \"tracking:events\": 162,\n" + " \"tracking:firstVisit\": 1475320136,\n" + " \"tracking:lastVisit\": 1498054362,\n" + " \"tracking:sessions30\": 19,\n" + " \"tracking:timeSpent\": 10603,\n" + " \"value:potentialRevenue\": {\n" + " \"mean\": 2880.5258186397987,\n" + " \"stddev\": 504.1184773012633,\n" + " \"weight\": 1,\n" + " \"confidence\": 1\n" + " },\n" + " \"criteria:occupancy\": {\n" + " \"adults\": 2,\n" + " \"children\": 2,\n" + " \"infants\": 0\n" + " }\n" + "}"; final Pattern pattern = Pattern.compile(regex); 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