Regular Expressions 101

Save & Manage Regex

  • Current Version: 1
  • Save & Share
  • Community Library

Flavor

  • PCRE2 (PHP)
  • ECMAScript (JavaScript)
  • Python
  • Golang
  • Java
  • .NET 7.0 (C#)
  • Rust
  • PCRE (Legacy)
  • Regex Flavor Guide

Function

  • Match
  • Substitution
  • List
  • Unit Tests
Sponsors
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
Processing...

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 = "wald493#2"; final String string = "\n" + "//zeigt nur 1nen Eintrag an\n\n" + "export default function SchuelerEintrag({Schueler, onDelete, onEdit}){\n\n\n\n" + " return(\n\n" + " <div>\n" + " <br></br>\n" + " <h1>Name: {Schueler.name}</h1>\n" + " <p>Money: {Schueler.money}</p>\n\n" + " <button type = \"button\" className=\"bg-red-500 py-2 px-4 hover:bg-red-400\" onClick={() => onDelete(Schueler.id)}>\n" + " Delete\n" + " </button>\n\n" + " <button type =\"button\" className=\"bg-yellow-500 py-2 px-4 hover:bg-red-400\" onClick={() => onEdit(Schueler)}>\n" + " Edit\n\n" + " </button>\n\n" + " \n\n" + " </div>\n\n\n\n" + " )\n\n" + "//SchülerForm\n\n" + "import { Sumana } from \"next/font/google\";\n" + "import { useForm, Controller } from \"react-hook-form\";\n" + "import { z } from \"zod\";\n" + "import {zodResolver} from \"@hookform/resolvers/zod\"\n" + "import { useEffect } from \"react\";\n\n\n" + "const SchuelerSchema = z.object({\n" + " name: z.string().min(1, \"Name ist zu kurz\"),\n" + " money: z.coerce.number({invalid_type_error: \"muss eine Zahl sein\"}).gt(0, \"Zahl muss größer als 0 sein\").int(\"muss eine ganze Zahl sein\") \n" + "})\n\n" + "try{\n\n" + "const result = SchuelerSchema.parse({name: \"\"})\n\n\n\n" + "} catch(error){\n\n\n" + "console.log(error.issues)\n\n" + "}\n\n" + "export default function SchuelerForm ({onSubmit, editData}){\n" + " const {\n" + " control,\n" + " handleSubmit,\n" + " reset,\n" + " formState: {errors}\n" + " } = useForm({\n" + " resolver: zodResolver(\n" + " SchuelerSchema\n" + " ),\n" + " defaultValues: {\n" + " name: \"\",\n" + " money: 0\n" + " }\n" + " })\n\n" + " useEffect(() => {\n\n" + " if(editData){\n" + " reset(editData)\n" + " }else{\n" + " reset({name: \"\", money: 0})\n" + " }\n\n" + " }, [editData, reset])\n\n" + " const submitHandler = (data) => {\n" + " onSubmit(data);\n" + " reset( {name: \"\", money: 0});\n" + " }\n" + " return(\n\n" + " <div>\n" + " <form \n" + " onSubmit={handleSubmit(submitHandler)}\n" + " >\n" + " <div>\n" + " <label>\n" + " name: \n" + " </label>\n\n" + " \n\n" + " <Controller\n" + " name=\"name\"\n" + " control={control}\n" + " render={({ field })=> (\n" + " <input className=\"bg-amber-300 text-black\"\n" + " {...field}\n" + " type = \"text\"\n" + " placeholder=\"Mustername\"\n" + " />\n" + " )}\n" + " /> \n\n" + " </div>\n\n" + " <div>\n" + " <label>\n" + " money:\n" + " </label>\n\n" + " <Controller\n" + " name=\"money\"\n" + " control={control}\n" + " render={({field}) => (\n" + " <input className=\"bg-amber-300 text-black\"\n" + " {...field}\n" + " type = \"number\"\n" + " placeholder=\"0\"\n" + " />\n" + " )}\n" + " />\n\n" + " </div>\n\n" + " <button type = \"sumbit\">\n" + " Speichern\n" + " </button>\n\n\n" + " \n" + " \n" + " </form>\n\n" + " <br></br>\n\n" + " {\n" + " errors.name && (<p>{errors.name.message}</p>)\n" + " \n" + " }\n\n" + " {\n" + " errors.money && (<p>{errors.money.message}</p>)\n" + " }\n\n" + " \n" + "<br></br>\n\n" + " </div> \n\n" + " \n\n" + " );\n" + "}\n\n" + "//SchülerListe\n\n" + "import SchuelerEintrag from \"./SchuelerEintrag\"\n\n" + "export default function SchuelerListe({Liste, handleDelete, handleEdit}){\n\n" + " if(Liste.length == 0){\n" + " return(\n" + " <p>keine Einträge</p>\n" + " )\n" + " }\n\n" + " return(\n" + " <div>\n" + " {\n" + " Liste.map((Eintrag) => (<SchuelerEintrag Schueler={Eintrag} onDelete={handleDelete} onEdit={handleEdit} key = {Eintrag.id}/>))\n" + " }\n" + " </div>\n" + " )\n\n" + " \n" + "}\n\n" + "//page.js\n\n" + "import Image from \"next/image\";\n" + "import SchuelerForm from \"./components/SchuelerForm\";\n" + "import SchuelerListe from \"./components/SchuelerListe\";\n\n" + "import { useState } from \"react\";\n\n\n" + "export default function Home() {\n\n" + " const [SchuelerEinträge, setSchuelerEinträge] = useState([]);\n" + " const [editData, setEditData] = useState(null);\n\n" + " const addItem = (data) => { \n" + " \n" + " if(editData){\n" + " setSchuelerEinträge((prev) => prev.map((s)=>(s.id === editData.id ? {...data, id: editData.id} : s) ) )\n" + " setEditData(null)\n" + " } else{\n" + " setSchuelerEinträge((prev)=> [...prev, {...data, id: Date.now()}])\n" + " }\n\n" + " \n\n\n" + " }\n\n" + " const handleEdit = (Schueler) => {\n" + " setEditData(Schueler)\n" + " }\n\n\n" + " const deleteItem = (id) => {\n" + " setSchuelerEinträge((prev) => prev.filter((Eintrag) => Eintrag.id != id))\n" + " } \n\n" + " \n" + " return (\n" + " <div>\n" + " <SchuelerForm onSubmit={addItem} editData={editData}/>\n" + " <SchuelerListe Liste={SchuelerEinträge} handleDelete={deleteItem} handleEdit={handleEdit}/>\n" + " </div>\n" + " );\n" + "}\n\n\n\n\n\n\n"; 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