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

/
/
gx

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 = "editor\\s*\\{[^\\{\\}\"]*\n\n" + "# Repeatedly match the key-value pairs\n" + "(?:\n" + " # Match from opening to closing double quote for the 'key'\n" + " \"[^\\\\\"]*\n" + " # Handle escaped characters: \\ followed by another character\n" + " (?: \\\\. [^\\\\\"]* )*\n" + " \"\n" + " # Then any whitespace between the 'key' and 'value'\n" + " \\s+\n" + " # Match from opening to closing double quote for the 'value'\n" + " \"[^\\\\\"]*\n" + " # Handle escaped characters: \\ followed by another character\n" + " (?: \\\\. [^\\\\\"]* )*\n" + " \"\n\n" + " # Match everything (especially whitespace) except these chars:\n" + " [^\\{\\}\"]*\n\n" + "|\n" + " # Key name may or may not be within quotes\n" + " \"? \\w+ \"? [^\\{\\}\"]*\n" + " \\{[^\\{\\}\"]*\n" + " (?:\n" + " \"[^\\\\\"]* (?: \\\\. [^\\\\\"]* )* \" \\s+ \"[^\\\\\"]* (?: \\\\. [^\\\\\"]* )* \"\n" + " [^\\{\\}\"]*\n" + " )*\n" + " \\} [^\\{\\}\"]*\n" + ")*\n\n" + "\\}"; final String string = "\"entity\"\n" + "{\n" + " \"id\" \"5040044\"\n" + " \"classname\" \"weapon_defibrillator_spawn\"\n" + " \"angles\" \"0 0 0\"\n" + " \"body\" \"0\"\n" + " \"disableshadows\" \"0\"\n" + " \"skin\" \"0\"\n" + " \"solid\" \"6\"\n" + " \"spawnflags\" \"3\"\n" + " \"origin\" \"449.47 5797.25 2856\"\n" + " editor\n" + " {\n" + " \"color\" \"0 0 200\"\n" + " \"visgroupshown\" \"1\"\n" + " \"visgroupautoshown\" \"1\"\n" + " \"logicalpos\" \"[-13268 14500]\"\n" + " \"helptext\" \"This is a \\\"help\\\" menu.\"\n" + " }\n" + " editor\n" + " {\n" + " \"color\" \"0 0 200\"\n" + " \"visgroupshown\" \"1\"\n" + " \"visgroupautoshown\" \"1\"\n" + " \"logicalpos\" \"[-13268 14500]\"\n" + " }\n" + " editor\n" + " {\n" + " \"color\" \"0 0 200\"\n" + " \"visgroupshown\" \"1\"\n" + " \"visgroupautoshown\" \"1\"\n" + " \"logicalpos\" \"[-13268 14500]\"\n" + " \"specialchars\" \"}\"\n" + " }\n" + " editor\n" + " {\n" + " \"child\" \"0 0 200\"\n" + " \"visgroupshown\" \"1\"\n" + " \"visgroupautoshown\" \"1\"\n" + " \"logicalpos\" \"[-13268 14500]\"\n" + " subgroup\n" + " {\n" + " \"child\" \"42 42 42\"\n" + " }\n" + " }\n" + "}\n"; final Pattern pattern = Pattern.compile(regex, Pattern.COMMENTS); 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