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

/
/
igm

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 = "(?#https://regex101.com/r/eO8pP0/)(?(DEFINE)(?<hex>[a-fA-F\\d])(?<hue>[+-]?(?:\\d{1,8}(?:\\.\\d{0,8})?|\\.\\d{0,8}))(?<percent>(?:\\d{1,2}|100)%)(?<channel>(?&percent)|25[0-5]|2[0-4]\\d|[0-1]\\d\\d|\\d{1,2})(?<rgb>\\h*(?&channel)\\h*(?:,\\h*(?&channel)\\h*){2})(?<hsl>\\h*(?&hue)\\h*(?:,\\h*(?&percent)\\h*){2})(?<alpha>1(?:\\.0*)?|0?\\.\\d{1,8}|0))^(?:#(?:(?&hex){6}|(?&hex){3})|rgb\\h*\\((?&rgb)\\)|hsl\\h*\\((?&hsl)\\)|rgba\\h*\\((?&rgb),\\h*(?&alpha)\\h*\\)|hsla\\h*\\((?&hsl),\\h*(?&alpha)\\h*\\)|inherit|initial|transparent|unset|current[cC]olor|(?# Named colors)aliceblue|antiquewhite|aqua|aquamarine|azure|beige|bisque|black|blanchedalmond|blue|blueviolet|brown|burlywood|cadetblue|chartreuse|chocolate|coral|cornflowerblue|cornsilk|crimson|cyan|darkblue|darkcyan|darkgoldenrod|darkgray|darkgreen|darkgrey|darkkhaki|darkmagenta|darkolivegreen|darkorange|darkorchid|darkred|darksalmon|darkseagreen|darkslateblue|darkslategray|darkslategrey|darkturquoise|darkviolet|deeppink|deepskyblue|dimgray|dimgrey|dodgerblue|firebrick|floralwhite|forestgreen|fuchsia|gainsboro|ghostwhite|gold|goldenrod|gray|green|greenyellow|grey|honeydew|hotpink|indianred|indigo|ivory|khaki|lavender|lavenderblush|lawngreen|lemonchiffon|lightblue|lightcoral|lightcyan|lightgoldenrodyellow|lightgray|lightgreen|lightgrey|lightpink|lightsalmon|lightseagreen|lightskyblue|lightslategray|lightslategrey|lightsteelblue|lightyellow|lime|limegreen|linen|magenta|maroon|mediumaquamarine|mediumblue|mediumorchid|mediumpurple|mediumseagreen|mediumslateblue|mediumspringgreen|mediumturquoise|mediumvioletred|midnightblue|mintcream|mistyrose|moccasin|navajowhite|navy|oldlace|olive|olivedrab|orange|orangered|orchid|palegoldenrod|palegreen|paleturquoise|palevioletred|papayawhip|peachpuff|peru|pink|plum|powderblue|purple|red|rosybrown|royalblue|saddlebrown|salmon|sandybrown|seagreen|seashell|sienna|silver|skyblue|slateblue|slategray|slategrey|snow|springgreen|steelblue|tan|teal|thistle|tomato|turquoise|violet|wheat|white|whitesmoke|yellow|yellowgreen)$"; final String string = "red\n" + "#f00\n" + "#ff0000\n" + "rgb(255,0,0)\n" + "rgb(100%, 0%, 0%)\n" + "hsl(0, 100%, 50%)\n" + "hsl(0., 100%, 50%)\n" + "hsl(.0, 100%, 50%)\n" + "hsl(0.0, 100%, 50%)\n" + "rgba(255, 0, 0, 0.5)\n" + "hsla(0, 100%, 50%, 0.5)\n" + "red\n" + "orange\n" + "antiquewhite\n" + "#0f0\n" + "#00ff00\n" + "rgba( 34, 12, 64, 0.3)\n" + "currentcolor\n" + "inherit\n" + "initial\n" + "unset"; final Pattern pattern = Pattern.compile(regex, Pattern.CASE_INSENSITIVE | Pattern.MULTILINE); 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