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

`
`
gmi

Test String

Substitution

Processing...

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 = "((?<field>[a-z0-9]*)=>)(?<value>\"[a-z0-9-_'/=> ]*\")"; final String string = "FldSelectAllowAdd=>\"0\" FldSelectFilter=>\"\" FldSelectFilterFld=>\"\" FldSelectForceSelection=>\"0\" FldSelectMultiple=>\"0\" FldSelectSize=>\"\" FldSelectType=>\"Values\"\n" + "FldTagLnkDisp2=>\"\" FldTagLnkDisplay=>\"\" FldTagLnkDistinct=>\"0\" FldTagLnkFld=>\"\" FldTagLnkOrderBy=>\"\" FldTagLnkOrderType=>\"\" FldTagLnkTbl=>\"\"\n" + "FldTagAPrefix=>\"None\" FldTagASuffix=>\"\" FldTagATarget=>\"\" FldTagAType=>\"\" FldTagCols=>\"\" FldTagHiddenValue=>\"\" FldTagImgHeight=>\"\" FldTagImgWidth=>\"\" FldTagMaxLength=>\"\" FldTagRows=>\"\" FldTagSize=>\"\" FldTagValues=>\"\"\n" + "FldAdd=>\"0\" FldAddOpt=>\"1\" FldAggregate=>\"\" FldAjax=>\"0\" FldAlias=>\"0\" FldAlign=>\"\" FldAlt=>\"\" FldAttribute=>\"100\" FldAutoFill=>\"0\" FldAutoIncrement=>\"0\" FldAutoUpdateValue=>\"\"\n" + "FldBasicSearch=>\"0\" FldBold=>\"0\"\n" + "FldCaption=>\"Updated At\" FldCheckDuplicate=>\"0\" FldColumnWidth=>\"\" FldColumnWrap=>\"0\"\n" + "FldDefault=>\"\" FldDtFormat=>\"7\"\n" + "FldEdit=>\"0\" FldEditCustomAttributes=>\"\" FldEditTableField=>\"\" FldErrMsg=>\"\" FldExport=>\"0\" FldExtendedBasicSearch=>\"0\"\n" + "FldFmtType=>\"Date/Time\"\n" + "FldGenerate=>\"1\" FldGpDigits=>\"-2\" FldGroupBy=>\"0\" FldGroupByShowSummary=>\"0\"\n" + "FldHrefFld=>\"\" FldHrefFldOrig=>\"0\" FldHtmlTag=>\"TEXT\" FldHtmlTagReadOnly=>\"0\"\n" + "FldIncLeadDigit=>\"-2\" FldIsPrimaryKey=>\"0\" FldItalic=>\"0\"\n" + "FldList=>\"0\"\n" + "FldMax=>\"\" FldMemoCRLFReplace=>\"0\" FldMemoMaxLength=>\"0\" FldMin=>\"\" FldMultiUpdate=>\"0\"\n" + "FldNumDigits=>\"0\"\n" + "FldOrder=>\"\" FldOrderBy=>\"0\"\n" + "FldPageIndex=>\"1\" FldParentSelect=>\"\" FldPopCalendar=>\"0\"\n" + "FldQuoteE=>\"'\" FldQuoteS=>\"'\"\n" + "FldRegister=>\"0\" FldRepeatColumns=>\"0\" FldReq=>\"0\" FldRequired=>\"0\" FldResizeHeight=>\"0\" FldResizeQuality=>\"75\" FldResizeWidth=>\"0\" FldRptAggAvg=>\"0\" FldRptAggMax=>\"0\" FldRptAggMin=>\"0\" FldRptAggSum=>\"0\"\n" + "FldSearch=>\"0\" FldSize=>\"26\" FldSourceField=>\"\" FldSourceName=>\"\" FldSourceTable=>\"\" FldSrchOpr=>\"=>\" FldSrchOpr2=>\"\" FldStrFunc=>\"\" FldSupport=>\"1\"\n" + "FldTitle=>\"\" FldType=>\"135\" FldTypeName=>\"TIMESTAMP\"\n" + "FldUniqueIdx=>\"0\" FldUploadPath=>\"\" FldUploadResize=>\"0\" FldUseDHTMLEditor=>\"0\" FldUseParen=>\"-2\"\n" + "FldValidate=>\"EURODATE\" FldView=>\"0\" FldViewCustomAttributes=>\"\" FldViewTag=>\"FORMATTED TEXT\" FldViewThumbnail=>\"0\"\n" + "FldZeroLen=>\"1\"\n" + "FileNameFld=>\"\" FileSizeFld=>\"\" FileTypeFld=>\"\"\n" + "ImageHeightFld=>\"\" ImageWidthFld=>\"\"\n" + "NativeDataType=>\"7\""; final String subst = "'${field}' => ${value},"; final Pattern pattern = Pattern.compile(regex, Pattern.MULTILINE | Pattern.CASE_INSENSITIVE); 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