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

/
/
gm

Test String

Substitution

Processing...

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 = "\\s*(<!--[\\s\\S]+?-->)"; final String string = " <header class=\"afl\">\n" + " <div class=\"openClose\">\n" + " <div class=\"line line1\"></div>\n" + " <div class=\"line line2\"></div>\n" + " <div class=\"line line3\"></div>\n" + " </div>\n" + " <div class=\"ssLogo\">\n" + " <div class=\"c1\">\n" + " <div class=\"c2\">SS</div>\n" + " </div>\n" + " </div>\n" + " <!-- <script data-xd>mcgu/a-/AAuE7mA5Yb1qpx76aqsJ131_TaqMRgH1jd5nVUYrO9yDGQ=s96-c</script> -->\n" + " <!-- <script data-xd>mcgu/a-/AAuE7mA5Yb1qpx76aqsJ131_TaqMRgH1jd5nVUYrO9yDGQ=s96-c</script><script data-xd>mcgu/a-/AAuE7mA5Yb1qpx76aqsJ131_TaqMRgH1jd5nVUYrO9yDGQ=s96-c</script>\n" + " <script data-xd>mcgu/a-/AAuE7mA5Yb1qpx76aqsJ131_TaqMRgH1jd5nVUYrO9yDGQ=s96-c</script><script data-xd>mcgu/a-/AAuE7mA5Yb1qpx76aqsJ131_TaqMRgH1jd5nVUYrO9yDGQ=s96-c</script>\n" + " <script data-xd>mcgu/a-/AAuE7mA5Yb1qpx76aqsJ131_TaqMRgH1jd5nVUYrO9yDGQ=s96-c</script><script data-xd>mcgu/a-/AAuE7mA5Yb1qpx76aqsJ131_TaqMRgH1jd5nVUYrO9yDGQ=s96-c</script>\n" + " <script data-xd>mcgu/a-/AAuE7mA5Yb1qpx76aqsJ131_TaqMRgH1jd5nVUYrO9yDGQ=s96-c</script><script data-xd>mcgu/a-/AAuE7mA5Yb1qpx76aqsJ131_TaqMRgH1jd5nVUYrO9yDGQ=s96-c</script>\n\n" + " <script data-xd>mcgu/a-/AAuE7mA5Yb1qpx76aqsJ131_TaqMRgH1jd5nVUYrO9yDGQ=s96-c</script><script data-xd>mcgu/a-/AAuE7mA5Yb1qpx76aqsJ131_TaqMRgH1jd5nVUYrO9yDGQ=s96-c</script>\n\n\n" + " tdhuitjhuio5hrtjhtryhtujhtohju -->\n" + " <div class=\"ssText\">Social Services</div>\n" + " <div class=\"menu\">\n" + " <div class=\"userData\">\n" + " <div class=\"logo\">\n" + " <img class=\"userpicture\" src=\"https://lh3.googleusercontent.com/a-/AAuE7mA5Yb1qpx76aqsJ131_TaqMRgH1jd5nVUYrO9yDGQ=s96-c\" alt=\"MD Real\" />\n" + " </div>\n" + " </div>\n" + " </div>\n" + " </header>\n" + " <aside class=\"leftSidebar open\" id=\"menu\">\n" + " <div class=\"controls\">\n" + " <div class=\"openClose\">\n" + " <div class=\"line line1\"></div>\n" + " <div class=\"line line2\"></div>\n" + " <div class=\"line line3\"></div>\n" + " </div>\n" + " </div>\n" + " <!-- <script data-xd>mcgu/a-/AAuE7mA5Yb1qpx76aqsJ131_TaqMRgH1jd5nVUYrO9yDGQ=s96-c</script> -->\n" + " <!-- <script data-xd>mcgu/a-/AAuE7mA5Yb1qpx76aqsJ131_TaqMRgH1jd5nVUYrO9yDGQ=s96-c</script><script data-xd>mcgu/a-/AAuE7mA5Yb1qpx76aqsJ131_TaqMRgH1jd5nVUYrO9yDGQ=s96-c</script>\n" + " <script data-xd>mcgu/a-/AAuE7mA5Yb1qpx76aqsJ131_TaqMRgH1jd5nVUYrO9yDGQ=s96-c</script><script data-xd>mcgu/a-/AAuE7mA5Yb1qpx76aqsJ131_TaqMRgH1jd5nVUYrO9yDGQ=s96-c</script>\n" + " <script data-xd>mcgu/a-/AAuE7mA5Yb1qpx76aqsJ131_TaqMRgH1jd5nVUYrO9yDGQ=s96-c</script><script data-xd>mcgu/a-/AAuE7mA5Yb1qpx76aqsJ131_TaqMRgH1jd5nVUYrO9yDGQ=s96-c</script>\n" + " <script data-xd>mcgu/a-/AAuE7mA5Yb1qpx76aqsJ131_TaqMRgH1jd5nVUYrO9yDGQ=s96-c</script><script data-xd>mcgu/a-/AAuE7mA5Yb1qpx76aqsJ131_TaqMRgH1jd5nVUYrO9yDGQ=s96-c</script>\n\n" + " <script data-xd>mcgu/a-/AAuE7mA5Yb1qpx76aqsJ131_TaqMRgH1jd5nVUYrO9yDGQ=s96-c</script><script data-xd>mcgu/a-/AAuE7mA5Yb1qpx76aqsJ131_TaqMRgH1jd5nVUYrO9yDGQ=s96-c</script>\n\n\n" + " tdhuitjhuio5hrtjhtryhtujhtohju -->\n" + " <div id=\"system\" class=\"system\" data-textarea=\"Social Services\">\n" + " <a href=\"\" data-content=\"Our Requirements\"></a>\n" + " <a href=\"\" data-content=\"API's List\"></a>\n" + " </div>\n" + " <div id=\"user\" class=\"userDatas\" data-textarea=\"User\">\n" + " <a href=\"\" data-content=\"About User\"></a>\n" + " <a href=\"\" data-content=\"User Requests\"></a>\n" + " <a href=\"\" data-content=\"Enabled API's\"></a>\n" + " </div>\n" + " </aside>\n" + " <section id=\"userDetails\"></section>\n" + " <section class=\"content\"></section>\n" + " <footer></footer>\n" + " <!-- <script data-xd>mcgu/a-/AAuE7mA5Yb1qpx76aqsJ131_TaqMRgH1jd5nVUYrO9yDGQ=s96-c</script> -->\n" + " <!-- <script data-xd>mcgu/a-/AAuE7mA5Yb1qpx76aqsJ131_TaqMRgH1jd5nVUYrO9yDGQ=s96-c</script><script data-xd>mcgu/a-/AAuE7mA5Yb1qpx76aqsJ131_TaqMRgH1jd5nVUYrO9yDGQ=s96-c</script>\n" + " <script data-xd>mcgu/a-/AAuE7mA5Yb1qpx76aqsJ131_TaqMRgH1jd5nVUYrO9yDGQ=s96-c</script><script data-xd>mcgu/a-/AAuE7mA5Yb1qpx76aqsJ131_TaqMRgH1jd5nVUYrO9yDGQ=s96-c</script>\n" + " <script data-xd>mcgu/a-/AAuE7mA5Yb1qpx76aqsJ131_TaqMRgH1jd5nVUYrO9yDGQ=s96-c</script><script data-xd>mcgu/a-/AAuE7mA5Yb1qpx76aqsJ131_TaqMRgH1jd5nVUYrO9yDGQ=s96-c</script>\n" + " <script data-xd>mcgu/a-/AAuE7mA5Yb1qpx76aqsJ131_TaqMRgH1jd5nVUYrO9yDGQ=s96-c</script><script data-xd>mcgu/a-/AAuE7mA5Yb1qpx76aqsJ131_TaqMRgH1jd5nVUYrO9yDGQ=s96-c</script>\n\n" + " <script data-xd>mcgu/a-/AAuE7mA5Yb1qpx76aqsJ131_TaqMRgH1jd5nVUYrO9yDGQ=s96-c</script><script data-xd>mcgu/a-/AAuE7mA5Yb1qpx76aqsJ131_TaqMRgH1jd5nVUYrO9yDGQ=s96-c</script>\n\n\n" + " tdhuitjhuio5hrtjhtryhtujhtohju -->"; final String subst = ""; final Pattern pattern = Pattern.compile(regex, Pattern.MULTILINE); final Matcher matcher = pattern.matcher(string); // The substituted value will be contained in the result variable final String result = matcher.replaceAll(subst); System.out.println("Substitution result: " + result); } }

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