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

/
/

Test String

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 = "^"; final String string = "class FinUrad\n" + "{\n" + " public string Kod { get; set; }\n" + " public string Nazev { get; set; }\n" + " public override string ToString()\n" + " {\n" + " return Nazev;\n" + " }\n" + "}\n\n" + "<Grid Margin=\"20\">\n" + " <Grid.RowDefinitions>\n" + " <RowDefinition Height=\"Auto\"/>\n" + " <RowDefinition Height=\"*\"/>\n" + " <RowDefinition Height=\"Auto\"/>\n" + " </Grid.RowDefinitions>\n" + " <StackPanel Grid.Row=\"0\" Margin=\"0,0,0,10\">\n" + " <TextBlock Text=\"Jméno:\"/>\n" + " <TextBox x:Name=\"txtJmeno\" Margin=\"0,5,0,10\"/>\n\n" + " <TextBlock Text=\"Rodné číslo (XXXXXX/XXXX):\"/>\n" + " <TextBox x:Name=\"txtRC\" Margin=\"0,5,0,10\"/>\n\n" + " <TextBlock Text=\"Finanční úřad:\"/>\n" + " <ComboBox x:Name=\"comboFinUrady\" DisplayMemberPath=\"Nazev\" Margin=\"0,5,0,10\"/>\n\n" + " <TextBlock Text=\"Zpráva:\"/>\n" + " <TextBox x:Name=\"txtZprava\" AcceptsReturn=\"True\" Height=\"80\" Margin=\"0,5,0,10\"/>\n" + " </StackPanel>\n" + " <StackPanel Grid.Row=\"2\" Orientation=\"Horizontal\" HorizontalAlignment=\"Right\">\n" + " <Button x:Name=\"btnZobrazitHistorii\" Content=\"Zobrazit historii\" Click=\"btnZobrazitHistorii_Click\"/>\n" + " \n" + " <Button x:Name=\"btnOdeslat\" Content=\"Odeslat\" Click=\"btnOdeslat_Click\"/>\n" + " </StackPanel>\n" + "</Grid>\n\n" + "public partial class MainWindow : Window\n" + "{\n" + " private ObservableCollection<FinUrad> urady = new();\n" + " private const string ApiUrl = \"https://csharp.janjanousek.cz/api/financni-urady/\";\n" + " private const string ApiKey = \"VSB\";\n" + " public MainWindow()\n" + " {\n" + " InitializeComponent();\n" + " LoadFinUrady();\n" + " }\n" + " private async void LoadFinUrady()\n" + " {\n" + " while (true)\n" + " {\n" + " try\n" + " {\n" + " using HttpClient client = new();\n" + " client.DefaultRequestHeaders.Add(\"x-api-key\", ApiKey);\n" + " var response = await client.GetAsync(ApiUrl);\n" + " if (response.StatusCode == System.Net.HttpStatusCode.TooManyRequests)\n" + " {\n" + " if (response.Headers.TryGetValues(\"Retry-After\", out var values))\n" + " {\n" + " int secods = int.Parse(values.First());\n" + " await Task.Delay(secods * 1000);\n" + " continue;\n" + " }\n" + " }\n" + " response.EnsureSuccessStatusCode();\n" + " var xmlString = await response.Content.ReadAsStringAsync();\n" + " \n" + " var xml = XDocument.Parse(xmlString);\n" + " var polozky = xml.Descendants(\"POLOZKA\");\n" + " foreach (var elem in polozky)\n" + " {\n" + " string id = elem.Element(\"CHODNOTA\")?.Value;\n" + " string name = elem.Element(\"ZKRTEXT\")?.Value;\n" + " if (!string.IsNullOrEmpty(id) && !string.IsNullOrEmpty(name))\n" + " {\n" + " urady.Add(new FinUrad { Kod = id, Nazev = name });\n" + " }\n" + " }\n" + " comboFinUrady.ItemsSource = urady;\n" + " comboFinUrady.SelectedIndex = 0;\n" + " break;\n" + " }\n" + " catch (Exception ex)\n" + " {\n" + " MessageBox.Show(\"Chyba pri nacitani financnich uradu: \" + ex.Message);\n" + " break;\n" + " }\n" + " }\n" + " }\n" + " private void btnOdeslat_Click(object sender, RoutedEventArgs e)\n" + " {\n" + " string jmeno = txtJmeno.Text;\n" + " string rc = txtRC.Text;\n" + " var urad = comboFinUrady.SelectedItem as FinUrad;\n" + " string zprava = txtZprava.Text;\n" + " if(string.IsNullOrEmpty(jmeno) || string.IsNullOrEmpty(rc) || urad == null || string.IsNullOrEmpty(zprava) || zprava.Length < 10)\n" + " {\n" + " MessageBox.Show(\"Všechna pole musí být vyplněna a zpráva musí mít alespoň 10 znaků.\");\n" + " return;\n" + " }\n" + " if(!System.Text.RegularExpressions.Regex.IsMatch(rc, @\"^\\d{6}/\\d{4}$\"))\n" + " {\n" + " MessageBox.Show(\"Rodné číslo musí mít formát 123456/1234.\");\n" + " return;\n" + " }\n" + " SaveToDatabase(jmeno, rc, urad.Kod, urad.Nazev, zprava);\n" + " new ResultsWindow().Show();\n" + " }\n" + " private void btnZobrazitHistorii_Click(object sender, RoutedEventArgs e)\n" + " {\n" + " new ResultsWindow().Show();\n" + " }\n" + " private void SaveToDatabase(string jmeno, string rc, string idUrad, string nazevUrad, string zprava)\n" + " {\n" + " string dbPath = \"formulare.db\";\n" + " if(!File.Exists(dbPath))\n" + " {\n" + " using var connection = new SqliteConnection($\"Data Source={dbPath}\");\n" + " connection.Open();\n" + " var cmd = connection.CreateCommand();\n" + " cmd.CommandText = @\"\n" + " CREATE TABLE IF NOT EXISTS Formulare (\n" + " Id INTEGER PRIMARY KEY AUTOINCREMENT,\n" + " Jmeno TEXT NOT NULL,\n" + " RodneCislo TEXT NOT NULL,\n" + " IdUrad TEXT NOT NULL,\n" + " NazevUrad TEXT NOT NULL,\n" + " Zprava TEXT NOT NULL\n" + " )\";\n" + " cmd.ExecuteNonQuery();\n" + " }\n" + " using var conn = new SqliteConnection($\"Data Source={dbPath}\");\n" + " conn.Open();\n" + " var insert = conn.CreateCommand();\n" + " insert.CommandText = @\"\n" + " INSERT INTO Formulare (Jmeno, RodneCislo, IdUrad, NazevUrad, Zprava)\n" + " VALUES ($jmeno, $rc, $idUrad, $nazevUrad, $zprava)\";\n" + " insert.Parameters.AddWithValue(\"$jmeno\", jmeno);\n" + " insert.Parameters.AddWithValue(\"$rc\", rc);\n" + " insert.Parameters.AddWithValue(\"$idUrad\", idUrad);\n" + " insert.Parameters.AddWithValue(\"$nazevUrad\", nazevUrad);\n" + " insert.Parameters.AddWithValue(\"$zprava\", zprava);\n" + " insert.ExecuteNonQuery();\n" + " }\n" + "}\n\n" + "<Grid>\n" + " <ListBox x:Name=\"lstHistorie\"/>\n" + "</Grid>\n\n" + "public partial class ResultsWindow : Window\n" + "{\n" + " public ResultsWindow()\n" + " {\n" + " InitializeComponent();\n" + " LoadData();\n" + " }\n" + " private void LoadData()\n" + " {\n" + " string dbPath = \"formulare.db\";\n" + " if (!File.Exists(dbPath)) return;\n" + " using var conn = new SqliteConnection($\"Data Source={dbPath}\");\n" + " conn.Open();\n" + " var cmd = conn.CreateCommand();\n" + " cmd.CommandText = @\"\n" + " SELECT Jmeno, RodneCislo, IdUrad, NazevUrad, Zprava\n" + " FROM Formulare\";\n" + " using var reader = cmd.ExecuteReader();\n" + " while (reader.Read())\n" + " {\n" + " lstHistorie.Items.Add($\"Jméno: {reader.GetString(0)}, RČ: {reader.GetString(1)}, Úřad: {reader.GetString(2)}, Zpráva: {reader.GetString(3)}\");\n" + " }\n" + " }\n" + "}"; final Pattern pattern = Pattern.compile(regex); final Matcher matcher = pattern.matcher(string); if (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