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

/
/

Test String

Code Generator

Generated Code

import java.util.regex.Matcher; import java.util.regex.Pattern; public class Example { public static void main(String[] args) { final String regex = "\\d"; final String string = "The rundown\n" + "The modern monitoring stack is increasingly diverse and complex. \n" + "Represented among the top 10 most popular tools are solutions for systems monitoring, APM, web and user monitoring, and log management.\n" + "The top five monitoring challenges:\n" + "1) Quickly remediating service disruptions\n" + "2) Reducing alert noise\n" + "3) Securing budget for the proper tools\n" + "4) Quickly identifying service disruptions\n" + "5) Migrating services to the cloud\n" + "IT teams are feeling alert pain more than ever before.\n" + "Almost half of those surveyed receive over 50 alerts per day from their tools, and about a quarter receive more than 100.\n" + "Alert floods have a clear and substantial effect on remediation. \n" + "Of those who receive 100+ alerts per day, only 17% are able to investigate and remediate the majority (75-100%) within 24 hours.\n" + "Strategic monitoring is clearly important, but execution is lacking.\n" + "80% agree that strategic monitoring is important to their organization, but only 12% are very satisfied.\n" + "A good monitoring strategy goes a long way.\n" + "Respondents who are satisfied with their organization’s monitoring strategy find critical IT issues much easier to handle and report the best rates of remediation. In addition, organizations with a defined monitoring process are better equipped to respond to alerts.\n" + "IT performance is increasingly tied to business performance.\n" + "Customer satisfaction and SLA compliance take the lead as the most common KPIs to measure IT performance, outranking “traditional” metrics, such as MTTR and incident volume.\n" + "Good news for budgets, but not for ROI.\n" + "Only 16% anticipate a decrease to their overall IT budget in 2016, while a third expect it to increase. However, a dismal 9% agreed that they were very satisfied with their organization’s monitoring strategy, based on overall investment\n"; final Pattern pattern = Pattern.compile(regex); final Matcher matcher = pattern.matcher(string); if (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