Regular Expressions 101

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  • Substitution
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  • Unit Tests (1)

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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

/
/

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 = "^(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$Oracle Software Owner for Each Oracle Software Product\n\n" + "You can create a single user (for example, oracle) to own both Oracle Database, and\n\n" + "Oracle Restart installations.\n\n" + "However, Oracle recommends that you create one software owner to own each Oracle\n\n" + "software installation (typically, oracle, for the database software and grid for the\n\n" + "Oracle Restart owner user).\n\n" + "You must create at least one software owner the first time you install Oracle software\n\n" + "on the system.\n\n" + "Note:\n\n" + "In Oracle documentation, a user created to own only Oracle Grid\n\n" + "Infrastructure software installations is called the grid user. A user created to\n\n" + "own either all Oracle installations, or only Oracle database installations, is\n\n" + "called the oracle user.\n\n" + "Standard Oracle Database Groups for Job Role Separation\n\n" + "Review the standard Oracle Database groups.\n\n" + "The following is a list of standard Oracle Database groups. These groups provide\n\n" + "operating system authentication for database administration system privileges:\n\n" + "Note:\n\n" + "All these groups are automatically created as a part of Oracle Database\n\n" + "installation on Windows.\n\n" + "• The OSDBA group (ORA_DBA)\n\n" + "Use this group the first time you install Oracle Database software on the system.\n\n" + "This group identifies operating system user accounts that have database\n\n" + "administrative privileges (the SYSDBA privilege) for all database instances running\n\n" + "on the server.\n\n" + "Members of the ORA_DBA group do not have SYSASM privileges on Oracle ASM\n\n" + "instances, which are needed for mounting and dismounting disk groups.\n\n" + "• The OSOPER group for Oracle Database (ORA_OPER)\n\n" + "Use this group if you want a separate group of operating system users to have a\n\n" + "limited set of database administrative privileges for starting up and shutting down\n\n" + "the database (the SYSOPER privilege).\n\n" + "• The OSDBA group for a particular Oracle home (ORA_HOMENAME_DBA)\n\n" + "This group is created the first time you install Oracle Database software into a new\n\n" + "Oracle home. This group identifies operating system user accounts that have\n\n" + "Chapter 4\n\n" + "Creating Required Operating System Groups and Users\n\n" + "4-8"; final String string = "10.1.1.1f"; final String subst = ""; 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.replaceFirst(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