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

/
/
gmi

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 = "<a\\b[^>]*href\\s*=\\s*\"cid[^\"]*\"[^>]*>.*<\\/a>"; final String string = "<html>\n" + "<head>\n" + "<meta http-equiv=\"Content-Type\" content=\"text/html; charset=utf-8\">\n" + "<meta name=\"Generator\" content=\"Microsoft Exchange Server\">\n" + "<!-- converted from rtf -->\n" + "<style><!-- .EmailQuote { margin-left: 1pt; padding-left: 4pt; border-left: #800000 2px solid; } --></style>\n" + "</head>\n" + "<body>\n" + "<font face=\"Arial\" size=\"2\"><span style=\"font-size:10pt;\">\n" + "<div>notes</div>\n" + "<div><font face=\"Calibri\" size=\"2\"><span style=\"font-size:11pt;\"><img src=\"cid:0DF540471453B832E300400FF03B0900CFEC1201@1\"> <a href=\"cid:74D8EEA6180AD131B48DC59373FABBABD7E361BB@1\">GoodGEMSinstall.docx</a> </span></font></div>\n" + "<div><font face=\"Calibri\" size=\"2\"><span style=\"font-size:11pt;\">&nbsp;</span></font></div>\n" + "<div><font face=\"Calibri\" size=\"2\"><span style=\"font-size:11pt;\"><b>some</b> <span style=\"background-color:yellow;\">formatted</span> <font size=\"6\" color=\"red\"><span style=\"font-size:22pt;\">text</span></font></span></font></div>\n" + "<div><font face=\"Calibri\" size=\"2\" color=\"red\"><span style=\"font-size:11pt;\">&nbsp;</span></font></div>\n" + "<div><font face=\"Calibri\" size=\"2\"><span style=\"font-size:11pt;\"><a href=\"cid:A559E9B55081418F53A3B0914D29351714C64825@1\">PowerShell_transcript.20140506143510.txt</a> </span></font></div>\n" + "<div><font face=\"Calibri\" size=\"2\"><span style=\"font-size:11pt;\">&nbsp;</span></font></div>\n" + "<div><font face=\"Calibri\" size=\"2\"><span style=\"font-size:11pt;\"><a href=\"http://www.google.com\"><font color=\"blue\"><u>www.google.com</u></font></a></span></font></div>\n" + "<div><font face=\"Calibri\" size=\"2\"><span style=\"font-size:11pt;\">&nbsp;</span></font></div>\n" + "<div><font face=\"Calibri\" size=\"2\"><span style=\"font-size:11pt;\">some links <a href=\"http://www.test.fr\"><font color=\"blue\"><u>www.test.fr</u></font></a> </span></font></div>\n" + "<div><font face=\"Calibri\" size=\"2\"><span style=\"font-size:11pt;\">&nbsp;</span></font></div>\n" + "</span></font>\n" + "</body>\n" + "</html>\n"; final String subst = ""; final Pattern pattern = Pattern.compile(regex, Pattern.MULTILINE | Pattern.CASE_INSENSITIVE); 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