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

/
/

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 = "(\\<meta([\\s]*(name=\"viewport\"){1})[\\w\\d\\s\\.\\-,=]*(content=\"){1}[\\w\\d\\s\\.\\-,=]*(viewport-fit=cover){1}[\\w\\d\\s\\.\\-,=\"]+\\/\\>)"; final String string = "<!DOCTYPE html>\n" + "<html lang=\"en\">\n" + " <head>\n" + " <meta charset=\"utf-8\" />\n" + " <title>Ionic App</title>\n\n" + " <base href=\"/\" />\n\n" + " <!-- viewport-fit on multiline meta -->\n" + " <meta name=\"viewport\"\n" + " content=\"viewport-fit=cover, width=device-width, initial-scale=1.0, minimum-scale=1.0, maximum-scale=1.0, user-scalable=no\"\n" + " />\n" + " <meta\n" + " name=\"viewport\" content=\"viewport-fit=cover, width=device-width, initial-scale=1.0, minimum-scale=1.0, maximum-scale=1.0, user-scalable=no\"\n" + " />\n" + " <meta\n" + " name=\"viewport\"\n" + " content=\"viewport-fit=cover, width=device-width, initial-scale=1.0, minimum-scale=1.0, maximum-scale=1.0, user-scalable=no\"\n" + " />\n\n" + " <!-- viewport-fit on singleline content at the start -->\n" + " <meta name=\"viewport\" content=\"viewport-fit=cover, width=device-width, initial-scale=1.0, minimum-scale=1.0, maximum-scale=1.0, user-scalable=no\" />\n\n" + " <!-- viewport-fit on singleline content at the end -->\n" + " <meta name=\"viewport\" content=\"width=device-width, initial-scale=1.0, minimum-scale=1.0, maximum-scale=1.0, user-scalable=no, viewport-fit=cover\" />\n\n" + " <meta name=\"format-detection\" content=\"telephone=no\" />\n" + " <meta name=\"msapplication-tap-highlight\" content=\"no\" />\n\n" + " <link rel=\"icon\" href=\"assets/icon/favicon.ico\" />\n\n" + " <!-- add to homescreen for ios -->\n" + " <meta name=\"apple-mobile-web-app-capable\" content=\"yes\" />\n" + " <meta name=\"apple-mobile-web-app-status-bar-style\" content=\"black\" />\n" + " </head>\n" + " <body>\n" + " <app-root></app-root>\n" + " </body>\n" + "</html>\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