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

import java.util.regex.Matcher; import java.util.regex.Pattern; public class Example { public static void main(String[] args) { final String regex = ",{0,1} \\w+.(\\w+), \\w+.(\\w+)"; final String string = " v1.VAC_ID, v2.VAC_ID\n" + ", v1.PAC_ID, v2.PAC_ID\n" + ", v1.ICL_CPI, v2.ICL_CPI\n" + ", v1.VAC_TVA, v2.VAC_TVA\n" + ", v1.TVA_SID, v2.TVA_SID\n" + ", v1.VAC_DAD, v2.VAC_DAD\n" + ", v1.VAC_DAD_A, v2.VAC_DAD_A\n" + ", v1.VAC_DAD_M, v2.VAC_DAD_M\n" + ", v1.VAC_DAD_H, v2.VAC_DAD_H\n" + ", v1.VAC_DOS, v2.VAC_DOS\n" + ", v1.VAC_CPV, v2.VAC_CPV\n" + ", v1.VAC_TAC, v2.VAC_TAC\n" + ", v1.VAC_OIN, v2.VAC_OIN\n" + ", v1.PRO_ID, v2.PRO_ID\n" + ", v1.RCV_ID, v2.RCV_ID\n" + ", v1.ID_HORA, v2.ID_HORA\n" + ", v1.COUNT, v2.COUNT\n" + ", v1.ASS_SEXE, v2.ASS_SEXE\n" + ", v1.ASS_DNA, v2.ASS_DNA\n" + ", v1.ASS_DNA_A, v2.ASS_DNA_A\n" + ", v1.EDAT, v2.EDAT\n" + ", v1.UPR_CUP, v2.UPR_CUP\n" + ", v1.UPR_CUP_T, v2.UPR_CUP_T\n" + ", v1.PAC_NIA, v2.PAC_NIA\n" + ", v1.ASS_CSA, v2.ASS_CSA\n" + ", v1.ICL_UP, v2.ICL_UP\n" + ", v1.ICL_BAC, v2.ICL_BAC\n" + ", v1.ICP_UP_ORIGINAL, v2.ICP_UP_ORIGINAL\n" + ", v1.VAC_DED, v2.VAC_DED\n" + ", v1.VAC_DED_TRUNC, v2.VAC_DED_TRUNC\n" + ", v1.ICL_BAD, v2.ICL_BAD\n" + ", v1.ICL_BAD_TRUNC, v2.ICL_BAD_TRUNC\n" + ", v1.COUNT_ACTIUS, v2.COUNT_ACTIUS\n" + ", v1.VAC_LOT, v2.VAC_LOT\n" + ", v1.VAC_VIA, v2.VAC_VIA\n" + ", v1.VAC_DCV, v2.VAC_DCV\n" + ", v1.VAC_LAD, v2.VAC_LAD\n" + ", v1.VAC_MNV, v2.VAC_MNV\n" + ", v1.VAC_GPE, v2.VAC_GPE\n" + ", v1.VAC_GPV, v2.VAC_GPV\n" + ", v1.VAC_MCO, v2.VAC_MCO\n" + ", v1.TSI_LOCALITAT, v2.TSI_LOCALITAT\n" + ", v1.TSI_CPOSTAL, v2.TSI_CPOSTAL\n" + ", v1.PAC_CIP, v2.PAC_CIP\n" + ", v1.VAC_DAD_TRUNC, v2.VAC_DAD_TRUNC"; final String subst = "or decode(v1.$1, v2.$2, 1, 0) = 0"; final Pattern pattern = Pattern.compile(regex, Pattern.MULTILINE); 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