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
  • Match everything enclosed
    (?:...)
  • Capture everything enclosed
    (...)
  • 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 = "\\b((?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)(?:(?<!\\.)\\b|\\.)){4}"; final String string = "#Ejemplos de codigo fuente del lenguaje de programacion Ruby\n\n" + "#Aritmetica basica\n" + "resultado='5 * (12 - 8) + -15'\n" + "puts resultado\n" + "puts 98 + (59872 / (13 * 8)) * -52\n\n" + "#Textos\n" + "puts \"Hola, mundo!\"\n" + "puts \"\"\n" + "puts \"Adiós.\"\n" + "puts \"Me gusta\" + \"el pastel de manzana.\"\n" + "puts \"Mi IP es: 192.168.9.10\"\n" + "puts \"ragustin726@gmail.com\"\n" + "puts \"https://www.facebook.com\"\n" + "puts \"31/01/2021/\"\n\n" + "277.893.21.2\n\n" + "#Variables\n" + "myString = '...puedes decir eso de nuevo...'\n" + "puts myString\n" + "name = 'Patricia Rosanna Jessica Mildred Oppenheimer'\n" + "ip= 10.0.0.1\n" + "correo='roberto_840@hotmail.com'\n" + "direccion='https://www.google.com'\n" + "fecha = '19/07/2001'\n\n" + "#Concatenaciones\n" + "puts 'Me llamo ' + name + '.'\n" + "puts 'Wow! \"' + name + '\" es un nombre realmente largo!'\n" + "composer1 = 'Mozart'\n" + "puts composer1 + ' fue \"el amo\", en su día.'\n" + "composer = 'Beethoven'\n" + "puts 'Pero yo prefiero a ' + composer1 + ', personalmente.'\n\n" + "#Conversiones\n" + "var1 = 2\n" + "var2 = '5'\n" + "puts var1.to_s + var2\n" + "var1 = 2\n" + "var2 = '5'\n" + "puts var1.to_s + var2\n" + "puts var1 + var2.to_i\n\n" + "#Condicionales \n" + "puts 1 > 2\n" + "puts 1 < 2\n" + "puts 5 >= 5\n" + "puts 5 <= 4\n" + "puts 1 == 1\n" + "puts 2 != 1\n" + "puts 'gato' < 'perro'\n\n" + "#Ramificaciones\n" + "puts 'Hola, y bienvenido a la clase de 7mo año.'\n" + "puts 'Me llamo Mrs. Gabbard. ¿Tú nombre es...?'\n" + "nombre = gets.chomp\n\n" + "if nombre == nombre.capitalize\n" + " puts 'Por favor, toma asiento ' + nombre + '.'\n" + "else\n" + " puts '¿' + nombre + '? Quieres decir ' + nombre.capitalize + ', ¿cierto?'\n" + " puts '¿No sabes escribir tu propio nombre?'\n" + " respuesta = gets.chomp\n\n" + " if respuesta.downcase == 'si'\n" + " puts '¡Hum! Bueno, ¡siéntese!'\n" + " else\n" + " puts '¡SALGA DEL SALON!'\n" + " end\n" + "end\n\n" + "#Bucles\n" + "comando = ''\n" + "while comando != 'adios'\n" + " puts comando\n" + " comando = gets.chomp\n" + "end\n" + "puts '¡Vuelve pronto!'\n\n" + "#Operadores logicos\n" + "edad=18\n" + "sexo=\"Mujer\"\n" + "ocupacion=\"Estudiante\"\n" + "if edad>=18 and sexo==\"Mujer\" and ocupacion=\"Estudiante\"\n" + " puts \"Mujer mayor de edad estudiante\"\n" + "end\n\n" + "edad=18\n" + "if edad>=18 or edad<=25\n" + " puts \"Tu edad esta entre los 18 y 25 años\"\n" + "end\n\n" + "#Modulos y potencias\n" + "puts 5**2\n" + "puts 5**0.5\n" + "puts 7/3\n" + "puts 7%3\n" + "puts 365%7\n\n" + "#Lectura de archivos\n" + "content1 = File.read(\"imagen.jpg\") # lee el archivo\n" + "content2 = File.read(\"contenido.png\")\n" + "lines = content.split(\"\\n\") # divide el contenido en líneas\n\n" + "# recorre las líneas y las imprime\n" + "lines.each do |line|\n" + " puts line\n" + "end"; 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