Regular Expressions 101

Save & Share

Flavor

  • PCRE2 (PHP >=7.3)
  • PCRE (PHP <7.3)
  • ECMAScript (JavaScript)
  • Python
  • Golang
  • Java 8
  • .NET 7.0 (C#)
  • Rust
  • Regex Flavor Guide

Function

  • Match
  • Substitution
  • List
  • Unit Tests

Tools

Sponsors
There are currently no sponsors. Become a sponsor today!
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

/
/
gm

Test String

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 = "[a-zA-Z]+[\\s\\,\\-\\&]*\\(*(?!\\d)[a-zA-Z\\€\\$]*\\)*\\s?"; final String string = "I. CASH FLOW FROM OPERATING ACTIVITIES\n" + "Profit attributable to owners of the parent 1,908 4,790\n" + "Depreciation, amortization, impairment and provisions (1) 927 1,080\n" + "Share in profit (loss) from equity-accounted companies (net of dividends received) 13 (63) (110)\n" + "Change in fair value of currency and commodity derivatives (2) 26 81 (3,608)\n" + "Capital gains and losses on asset disposals (3) (364) (20)\n" + "Profit (loss) from discontinued operations and disposal gain (before tax) (110) (990)\n" + "Profit attributable to non-controlling interests 55 62\n" + "Other (4) 217 1,206\n" + "Cash flow from operations, before change in working capital 2,651 2,410\n" + "Change in inventories and work-in-progress 14 (347) (308)\n" + "Change in operating receivables and payables (5) 15, 23, 26 219 561\n" + "Change in other receivables and payables 15, 23 (40) 63\n" + "Change in working capital (168) 316\n" + "TOTAL I (6) 2,483 2,726\n" + "II. CASH FLOW USED IN INVESTING ACTIVITIES\n" + "Capitalization of R&D expenditure (7) 10 (364) (286)\n" + "Payments for the purchase of intangible assets, net of proceeds (8) (324) (262)\n" + "Payments for the purchase of property, plant and equipment, net of proceeds (9) (704) (740)\n" + "Payments arising from the acquisition of investments or businesses, net (810) (54)\n" + "Proceeds arising from the sale of investments or businesses, net 2 3,060\n" + "Proceeds (payments) arising from the sale (acquisition) of investments and loans (10) 5 (1,974)\n" + "TOTAL II (2,195) (256)\n" + "III. CASH FLOW FROM (USED IN) FINANCING ACTIVITIES\n" + "Change in share capital – owners of the parent - -\n" + "Change in share capital – non-controlling interests (9) (4)\n" + "Acquisitions and disposals of treasury shares 18.b (38) (449)\n" + "Repayment of borrowings and long-term debt 22 (73) (66)\n" + "Increase in borrowings 22 682 1,058\n" + "Change in repayable advances 21 (24) (25)\n" + "Change in short-term borrowings 22 10 449\n" + "Dividends and interim dividends paid to owners of the parent 18.e (612) (340)\n" + "Dividends paid to non-controlling interests (30) (32)\n" + "TOTAL III (94) 591\n" + "CASH FLOW FROM OPERATING ACTIVITIES OF DISCONTINUED OPERATIONS TOTAL IV 171 14\n" + "CASH FLOW USED IN INVESTING ACTIVITIES OF DISCONTINUED OPERATIONS TOTAL V (111) (52)\n" + "CASH FLOW USED IN FINANCING ACTIVITIES OF DISCONTINUED OPERATIONS TOTAL VI (8) (198)\n" + "EFFECT OF CHANGES IN FOREIGN EXCHANGE RATES TOTAL VII 15 (17)\n" + "NET INCREASE IN CASH AND CASH EQUIVALENTS I+II+III+IV+V+VI+VII 261 2,808\n" + "Cash and cash equivalents at beginning of period 1,659 1,926\n" + "Cash and cash equivalents of discontinued operations at beginning of period 186 180\n" + "Cash and cash equivalents at end of period 16 1,926 4,914\n" + "Cash and cash equivalents of discontinued operations at end of period 180 -\n" + "NET INCREASE IN CASH AND CASH EQUIVALENTS 261 2,808"; final Pattern pattern = Pattern.compile(regex, Pattern.MULTILINE); final Matcher matcher = pattern.matcher(string); while (matcher.find()) { System.out.println("Full match: " + matcher.group(0)); for (int i = 1; i <= matcher.groupCount(); i++) { System.out.println("Group " + i + ": " + matcher.group(i)); } } } }

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