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

/
/
gm

Test String

Substitution

Processing...

Code Generator

Language

Generated Code

#include <MsgBoxConstants.au3> ; to declare the Constants of MsgBox Local $sRegex = "(?m)(\(\)\n[[:space:]]{1,}\{)|(\(\)[[:space:]]{1,}\{)" Local $sString = "// feedback thread" & @CRLF & _ "" & @CRLF & _ "import java.util.*;" & @CRLF & _ "" & @CRLF & _ "class Main" & @CRLF & _ "{" & @CRLF & _ " static Scanner scan = new Scanner(System.in);" & @CRLF & _ " static String deadEnd = "dead end--morphing backwards!";" & @CRLF & _ " static String gettingCloser = "You'r getting closer";" & @CRLF & _ " " & @CRLF & _ " // call this method after each decision has been made" & @CRLF & _ " public static void clearScreen() {" & @CRLF & _ " Scanner scan = new Scanner(System.in);" & @CRLF & _ " System.out.println("Press enter to continue.");" & @CRLF & _ " String x = scan.nextLine(); " & @CRLF & _ " System.out.print("\033[H\033[2J"); " & @CRLF & _ " System.out.flush(); " & @CRLF & _ " } " & @CRLF & _ "" & @CRLF & _ "" & @CRLF & _ "" & @CRLF & _ " public static void decisionZero()" & @CRLF & _ " {" & @CRLF & _ " System.out.println("Decision Point 0");" & @CRLF & _ " System.out.println("Choose a direction Mr. Mouse");" & @CRLF & _ " String direction = scan.nextLine();" & @CRLF & _ " switch (direction.toLowerCase()) {" & @CRLF & _ " case "n":" & @CRLF & _ " System.out.println("You chose north.");" & @CRLF & _ " System.out.println(deadEnd);" & @CRLF & _ " decisionZero();" & @CRLF & _ " break;" & @CRLF & _ "" & @CRLF & _ " case "s":" & @CRLF & _ " System.out.println("You chose south.");" & @CRLF & _ " System.out.println(gettingCloser);" & @CRLF & _ " decisionOne();" & @CRLF & _ " break;" & @CRLF & _ " " & @CRLF & _ " case "e":" & @CRLF & _ " System.out.println("You chose east.");" & @CRLF & _ " System.out.println(deadEnd);" & @CRLF & _ " decisionZero();" & @CRLF & _ " break;" & @CRLF & _ "" & @CRLF & _ " case "w":" & @CRLF & _ " System.out.println("You chose west.");" & @CRLF & _ " System.out.println(deadEnd);" & @CRLF & _ " decisionZero();" & @CRLF & _ " break;" & @CRLF & _ " " & @CRLF & _ " }" & @CRLF & _ " }" & @CRLF & _ " " & @CRLF & _ " public static void decisionOne()" & @CRLF & _ " {" & @CRLF & _ " System.out.println("Decision Point 1");" & @CRLF & _ " System.out.println("Choose a direction Mr. Mouse");" & @CRLF & _ " String direction = scan.nextLine();" & @CRLF & _ " switch (direction.toLowerCase()) {" & @CRLF & _ " case "n":" & @CRLF & _ " System.out.println("You chose north.");" & @CRLF & _ " System.out.println(deadEnd);" & @CRLF & _ " decisionZero();" & @CRLF & _ " break;" & @CRLF & _ "" & @CRLF & _ " case "s":" & @CRLF & _ " System.out.println("You chose south.");" & @CRLF & _ " System.out.println(deadEnd);" & @CRLF & _ " decisionZero();" & @CRLF & _ " break;" & @CRLF & _ "" & @CRLF & _ " case "e":" & @CRLF & _ " System.out.println("You chose east.");" & @CRLF & _ " System.out.println(deadEnd);" & @CRLF & _ " decisionZero();" & @CRLF & _ " break;" & @CRLF & _ "" & @CRLF & _ " case "w":" & @CRLF & _ " System.out.println("You chose west.");" & @CRLF & _ " System.out.println(gettingCloser);" & @CRLF & _ " decisionTwo();" & @CRLF & _ " break;" & @CRLF & _ "" & @CRLF & _ " }" & @CRLF & _ " }" & @CRLF & _ " " & @CRLF & _ " public static void decisionTwo()" & @CRLF & _ " {" & @CRLF & _ " System.out.println("Decision Point 2");" & @CRLF & _ " System.out.println("Choose a direction Mr. Mouse");" & @CRLF & _ " String direction = scan.nextLine();" & @CRLF & _ " int rndDecion = (int)(Math.random()*2);" & @CRLF & _ " switch (direction.toLowerCase()) {" & @CRLF & _ " case "n":" & @CRLF & _ " System.out.println("You chose north.");" & @CRLF & _ " System.out.println(gettingCloser);" & @CRLF & _ " decisionThree();" & @CRLF & _ " break;" & @CRLF & _ "" & @CRLF & _ " case "s":" & @CRLF & _ " System.out.println("You chose south.");" & @CRLF & _ " System.out.println(deadEnd);" & @CRLF & _ " switch (rndDecion) {" & @CRLF & _ " case 0:" & @CRLF & _ " decisionZero();" & @CRLF & _ " case 1:" & @CRLF & _ " decisionOne();" & @CRLF & _ " }" & @CRLF & _ " break;" & @CRLF & _ "" & @CRLF & _ " case "e":" & @CRLF & _ " System.out.println("You chose east.");" & @CRLF & _ " System.out.println(deadEnd);" & @CRLF & _ " switch (rndDecion) {" & @CRLF & _ " case 0:" & @CRLF & _ " decisionZero();" & @CRLF & _ " case 1:" & @CRLF & _ " decisionOne();" & @CRLF & _ " }" & @CRLF & _ " break;" & @CRLF & _ "" & @CRLF & _ " case "w":" & @CRLF & _ " System.out.println("You chose west.");" & @CRLF & _ " System.out.println(deadEnd);" & @CRLF & _ " switch (rndDecion) {" & @CRLF & _ " case 0:" & @CRLF & _ " decisionZero();" & @CRLF & _ " case 1:" & @CRLF & _ " decisionOne();" & @CRLF & _ " }" & @CRLF & _ " break;" & @CRLF & _ "" & @CRLF & _ " }" & @CRLF & _ " }" & @CRLF & _ " " & @CRLF & _ " public static void decisionThree()" & @CRLF & _ " {" & @CRLF & _ " System.out.println("Decision Point 3");" & @CRLF & _ " System.out.println("Choose a direction Mr. Mouse");" & @CRLF & _ " String direction = scan.nextLine();" & @CRLF & _ " int rndDecion = (int)(Math.random()*3);" & @CRLF & _ " switch (direction.toLowerCase()) {" & @CRLF & _ " case "n":" & @CRLF & _ " System.out.println("You chose north.");" & @CRLF & _ " System.out.println(gettingCloser);" & @CRLF & _ " decisionFour();" & @CRLF & _ " break;" & @CRLF & _ "" & @CRLF & _ " case "s":" & @CRLF & _ " System.out.println("You chose south.");" & @CRLF & _ " System.out.println(deadEnd);" & @CRLF & _ " switch (rndDecion) {" & @CRLF & _ " case 0:" & @CRLF & _ " decisionZero();" & @CRLF & _ " case 1:" & @CRLF & _ " decisionOne();" & @CRLF & _ " case 2:" & @CRLF & _ " decisionTwo();" & @CRLF & _ " }" & @CRLF & _ " break;" & @CRLF & _ "" & @CRLF & _ " case "e":" & @CRLF & _ " System.out.println("You chose east.");" & @CRLF & _ " System.out.println(deadEnd);" & @CRLF & _ " switch (rndDecion) {" & @CRLF & _ " case 0:" & @CRLF & _ " decisionZero();" & @CRLF & _ " case 1:" & @CRLF & _ " decisionOne();" & @CRLF & _ " case 2:" & @CRLF & _ " decisionTwo();" & @CRLF & _ " }" & @CRLF & _ " break;" & @CRLF & _ "" & @CRLF & _ " case "w":" & @CRLF & _ " System.out.println("You chose west.");" & @CRLF & _ " System.out.println(deadEnd);" & @CRLF & _ " switch (rndDecion) {" & @CRLF & _ " case 0:" & @CRLF & _ " decisionZero();" & @CRLF & _ " case 1:" & @CRLF & _ " decisionOne();" & @CRLF & _ " case 2:" & @CRLF & _ " decisionTwo();" & @CRLF & _ " }" & @CRLF & _ " break;" & @CRLF & _ "" & @CRLF & _ " }" & @CRLF & _ " }" & @CRLF & _ " " & @CRLF & _ " public static void decisionFour()" & @CRLF & _ " {" & @CRLF & _ " System.out.println("Decision Point 4");" & @CRLF & _ " System.out.println("Choose a direction Mr. Mouse");" & @CRLF & _ " String direction = scan.nextLine();" & @CRLF & _ " int rndDecion = (int)(Math.random()*4);" & @CRLF & _ " switch (direction.toLowerCase()) {" & @CRLF & _ " case "n":" & @CRLF & _ " System.out.println("You chose north.");" & @CRLF & _ " System.out.println(gettingCloser);" & @CRLF & _ " decisionFive();" & @CRLF & _ " break;" & @CRLF & _ "" & @CRLF & _ " case "s":" & @CRLF & _ " System.out.println("You chose south.");" & @CRLF & _ " System.out.println(deadEnd);" & @CRLF & _ " switch (rndDecion) {" & @CRLF & _ " case 0:" & @CRLF & _ " decisionZero();" & @CRLF & _ " case 1:" & @CRLF & _ " decisionOne();" & @CRLF & _ " case 2:" & @CRLF & _ " decisionTwo();" & @CRLF & _ " case 3:" & @CRLF & _ " decisionThree();" & @CRLF & _ " }" & @CRLF & _ " break;" & @CRLF & _ "" & @CRLF & _ " case "e":" & @CRLF & _ " System.out.println("You chose east.");" & @CRLF & _ " System.out.println(deadEnd);" & @CRLF & _ " switch (rndDecion) {" & @CRLF & _ " case 0:" & @CRLF & _ " decisionZero();" & @CRLF & _ " case 1:" & @CRLF & _ " decisionOne();" & @CRLF & _ " case 2:" & @CRLF & _ " decisionTwo();" & @CRLF & _ " case 3:" & @CRLF & _ " decisionThree();" & @CRLF & _ " }" & @CRLF & _ " break;" & @CRLF & _ "" & @CRLF & _ " case "w":" & @CRLF & _ " System.out.println("You chose west.");" & @CRLF & _ " System.out.println(deadEnd);" & @CRLF & _ " switch (rndDecion) {" & @CRLF & _ " case 0:" & @CRLF & _ " decisionZero();" & @CRLF & _ " case 1:" & @CRLF & _ " decisionOne();" & @CRLF & _ " case 2:" & @CRLF & _ " decisionTwo();" & @CRLF & _ " case 3:" & @CRLF & _ " decisionThree();" & @CRLF & _ " }" & @CRLF & _ " break;" & @CRLF & _ "" & @CRLF & _ " }" & @CRLF & _ " }" & @CRLF & _ "" & @CRLF & _ " public static void decisionFive()" & @CRLF & _ " {" & @CRLF & _ " System.out.println("Decision Point 5");" & @CRLF & _ " System.out.println("Choose a direction Mr. Mouse");" & @CRLF & _ " String direction = scan.nextLine();" & @CRLF & _ " int rndDecion = (int)(Math.random()*5);" & @CRLF & _ " switch (direction.toLowerCase()) {" & @CRLF & _ " case "n":" & @CRLF & _ " System.out.println("You chose north.");" & @CRLF & _ " System.out.println(deadEnd);" & @CRLF & _ " switch (rndDecion) {" & @CRLF & _ " case 0:" & @CRLF & _ " decisionZero();" & @CRLF & _ " case 1:" & @CRLF & _ " decisionOne();" & @CRLF & _ " case 2:" & @CRLF & _ " decisionTwo();" & @CRLF & _ " case 3:" & @CRLF & _ " decisionThree();" & @CRLF & _ " case 4:" & @CRLF & _ " decisionFour();" & @CRLF & _ " }" & @CRLF & _ " break;" & @CRLF & _ "" & @CRLF & _ " case "s":" & @CRLF & _ " System.out.println("You chose south.");" & @CRLF & _ " System.out.println(deadEnd);" & @CRLF & _ " switch (rndDecion) {" & @CRLF & _ " case 0:" & @CRLF & _ " decisionZero();" & @CRLF & _ " case 1:" & @CRLF & _ " decisionOne();" & @CRLF & _ " case 2:" & @CRLF & _ " decisionTwo();" & @CRLF & _ " case 3:" & @CRLF & _ " decisionThree();" & @CRLF & _ " case 4:" & @CRLF & _ " decisionFour();" & @CRLF & _ " }" & @CRLF & _ " break;" & @CRLF & _ "" & @CRLF & _ " case "e":" & @CRLF & _ " System.out.println("You chose east.");" & @CRLF & _ " System.out.println(deadEnd);" & @CRLF & _ " switch (rndDecion) {" & @CRLF & _ " case 0:" & @CRLF & _ " decisionZero();" & @CRLF & _ " case 1:" & @CRLF & _ " decisionOne();" & @CRLF & _ " case 2:" & @CRLF & _ " decisionTwo();" & @CRLF & _ " case 3:" & @CRLF & _ " decisionThree();" & @CRLF & _ " case 4:" & @CRLF & _ " decisionFour();" & @CRLF & _ " }" & @CRLF & _ " break;" & @CRLF & _ "" & @CRLF & _ " case "w":" & @CRLF & _ " System.out.println("You chose west.");" & @CRLF & _ " System.out.println(gettingCloser);" & @CRLF & _ " decisionSix();" & @CRLF & _ " break;" & @CRLF & _ "" & @CRLF & _ " }" & @CRLF & _ " }" & @CRLF & _ "" & @CRLF & _ " public static void decisionSix()" & @CRLF & _ " {" & @CRLF & _ " System.out.println("Decision Point 6");" & @CRLF & _ " System.out.println("Choose a direction Mr. Mouse");" & @CRLF & _ " String direction = scan.nextLine();" & @CRLF & _ " int rndDecion = (int)(Math.random()*5);" & @CRLF & _ " switch (direction.toLowerCase()) {" & @CRLF & _ " case "n":" & @CRLF & _ " System.out.println("You chose north.");" & @CRLF & _ " System.out.println(deadEnd);" & @CRLF & _ " switch (rndDecion) {" & @CRLF & _ " case 0:" & @CRLF & _ " decisionZero();" & @CRLF & _ " case 1:" & @CRLF & _ " decisionOne();" & @CRLF & _ " case 2:" & @CRLF & _ " decisionTwo();" & @CRLF & _ " case 3:" & @CRLF & _ " decisionThree();" & @CRLF & _ " case 4:" & @CRLF & _ " decisionFour();" & @CRLF & _ " }" & @CRLF & _ " break;" & @CRLF & _ "" & @CRLF & _ " case "s":" & @CRLF & _ " System.out.println("You chose south.");" & @CRLF & _ " System.out.println(deadEnd);" & @CRLF & _ " switch (rndDecion) {" & @CRLF & _ " case 0:" & @CRLF & _ " decisionZero();" & @CRLF & _ " case 1:" & @CRLF & _ " decisionOne();" & @CRLF & _ " case 2:" & @CRLF & _ " decisionTwo();" & @CRLF & _ " case 3:" & @CRLF & _ " decisionThree();" & @CRLF & _ " case 4:" & @CRLF & _ " decisionFour();" & @CRLF & _ " }" & @CRLF & _ " break;" & @CRLF & _ "" & @CRLF & _ " case "e":" & @CRLF & _ " System.out.println("You chose east.");" & @CRLF & _ " System.out.println("Victory cheese!");" & @CRLF & _ " break;" & @CRLF & _ "" & @CRLF & _ " case "w":" & @CRLF & _ " System.out.println("You chose west.");" & @CRLF & _ " System.out.println(gettingCloser);" & @CRLF & _ " switch (rndDecion) {" & @CRLF & _ " case 0:" & @CRLF & _ " decisionZero();" & @CRLF & _ " case 1:" & @CRLF & _ " decisionOne();" & @CRLF & _ " case 2:" & @CRLF & _ " decisionTwo();" & @CRLF & _ " case 3:" & @CRLF & _ " decisionThree();" & @CRLF & _ " case 4:" & @CRLF & _ " decisionFour();" & @CRLF & _ " }" & @CRLF & _ " break;" & @CRLF & _ "" & @CRLF & _ " }" & @CRLF & _ " }" & @CRLF & _ "" & @CRLF & _ "" & @CRLF & _ " // the main method is COMPLETE. Add/change nothing here." & @CRLF & _ " public static void main(String[] args) " & @CRLF & _ " {" & @CRLF & _ " decisionZero(); //only line in main method." & @CRLF & _ " }" & @CRLF & _ "" & @CRLF & _ "" & @CRLF & _ "" & @CRLF & _ "}" Local $sSubst = "()\n {\n clearScreen();" Local $sResult = StringRegExpReplace($sString, $sRegex, $sSubst) MsgBox($MB_SYSTEMMODAL, "Result", $sResult)

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 AutoIt, please visit: https://www.autoitscript.com/autoit3/docs/functions/StringRegExp.htm