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

r"
"
g

Test String

Substitution

Processing...

Code Generator

Generated Code

import java.util.regex.Matcher; import java.util.regex.Pattern; public class Example { public static void main(String[] args) { final String regex = "(\\(http[s]?:\\/\\/[\\w\\-\\_\\.\\/]*)(\\n)([\\w\\-\\_\\.\\/]*\\))"; final String string = "FIREVISION SPORTS features incredible Microprism Technology, which creates a\n" + "glowing streak of light, day or night. When you activate your FIREVISION ball\n" + "with a pair of cool FIREVISION Frames, you reveal a glow with a range over 100\n" + "feet/30 meters. The FIREVISION football is performance engineered to generate\n" + "spiraling streaks of light whenever you turn on your FIREVISION Frames and\n" + "throw it to a friend. Put glow in your game with the power of Microprism\n" + "Technology and the FIREVISION Football!\n\n" + "![Bright blazing light!](http://images.amazon.com/images/G/01/toys/detail-\n" + "page/2011/B008592HH2-1.jpg)\n\n" + " \n" + "**_FIREVISION Frames activate your ultra-bright glowing ball, day or night! \n" + "_**\n\n" + "![No charging!](http://images.amazon.com/images/G/01/toys/detail-\n" + "page/2011/B008592HH2-2.jpg)\n\n" + " \n" + "**_Battery-powered FIREVISION Frames let you play for hours without stopping to charge up the glow! \n" + "_**\n\n" + "**Lights out! Game on!** \n" + "Grab a friend and fire up your game with the FIREVISION football. Glowing\n" + "bright, day or night, FIREVISION Football keeps you playing at the top of your\n" + "game! Only you and other players equipped with the awesome FIREVISION Frames\n" + "can see the incredible glowing path carved through the air by the FIREVISION\n" + "Football. Choose your team, and change the color of the glow with red or green\n" + "FIREVISION Frames. With a range over 100 feet/30 meters, the FIREVISION\n" + "Football is the ultimate ball to bring glow to your game.\n\n" + "**Fire up the field!** \n" + "Put on your FIREVISION Frames and power up to bring glow to your game. The\n" + "performance-engineered FIREVISION Football features awesome new Microprism\n" + "Technology that generates a glow, even in the light. Choose your team, and\n" + "change the color of the glow with red or green FIREVISION Frames. Then, pass\n" + "to your teammates down field up to 100 feet away, and watch the ball generate\n" + "an amazing streak of light the entire way. When you play with FIREVISION gear,\n" + "you fire up the field!\n\n" + "**Microprism Technology blazes with energy!** \n" + "Choose your team with red or green FIREVISION Frames. Whichever color you\n" + "choose, that’s the color your Football will glow. Put on your Frames, power\n" + "up, and check out the incredible glow generated by the Microprism Technology\n" + "embedded in your ball. With a range over 100 feet/30 meters, you’ve got the\n" + "power you need to fire up any game.\n\n" + "**What's In The Box?** \n" + "Football with Microprism Technology, 2 pairs of FIREVISION Frames, and\n" + "instructions.\n\n" + "![Microprism Technology blazes with\n" + "energy!](http://images.amazon.com/images/G/01/toys/detail-\n" + "page/2011/B008592HH2-3.jpg)\n\n" + " \n" + "**_Glow with a range of more than 100 feet/30 meters!_**\n"; final String subst = "\\1\\3"; final Pattern pattern = Pattern.compile(regex); 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