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
Processing...

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 = "(?:```.*\\s+|\\s+```)"; final String string = "```html\n" + "<head>\n" + " <meta charset=\"UTF-8\">\n" + " <meta name=\"viewport\" content=\"width=device-width, initial-scale=1.0\">\n" + " <title>BPA vs. RPA</title>\n" + " <style>\n" + " table {\n" + " width: 80%;\n" + " margin: 20px auto;\n" + " border-collapse: collapse;\n" + " font-family: Arial, sans-serif;\n" + " background-color: #f9f9f9;\n" + " box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);\n" + " }\n" + " th, td {\n" + " padding: 15px;\n" + " text-align: left;\n" + " border-bottom: 1px solid #ddd;\n" + " }\n" + " th {\n" + " background-color: #ff785b;\n" + " color: white;\n" + " text-transform: uppercase;\n" + " }\n" + " tr:hover {\n" + " background-color: #f1f1f1;\n" + " }\n" + " tr:nth-child(even) {\n" + " background-color: #f2f2f2;\n" + " }\n" + " </style>\n" + "</head>\n" + "<body>\n" + " <table>\n" + " <tr>\n" + " <th>Aspect</th>\n" + " <th>Manual Collection</th>\n" + " <th>API-Based Collection</th>\n" + " </tr>\n" + " <tr>\n" + " <td>Speed</td>\n" + " <td>Slow</td>\n" + " <td>Fast</td>\n" + " </tr>\n" + " <tr>\n" + " <td>Accuracy</td>\n" + " <td>3-4% error rate</td>\n" + " <td>Very accurate</td>\n" + " </tr>\n" + " <tr>\n" + " <td>Data Volume</td>\n" + " <td>Limited</td>\n" + " <td>High capacity</td>\n" + " </tr>\n" + " <tr>\n" + " <td>Cost</td>\n" + " <td>Higher (labor)</td>\n" + " <td>Lower long-term</td>\n" + " </tr>\n" + " <tr>\n" + " <td>Consistency</td>\n" + " <td>Variable</td>\n" + " <td>Uniform</td>\n" + " </tr>\n" + " </table>\n" + "</body>\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