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

/
/
gm

Test String

Substitution

Processing...

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\\/ã]+').+(\\$[a-z_]+).+('[0-9%]+').+"; final String string = " $this->form->addQuickField('Id', $id, '50%' );\n" + " $this->form->addQuickField('Nome', $nome, '100%' , new TRequiredValidator);\n" + " $this->form->addQuickField('Cpf/Cnpj', $cpf_cnpj, '100%' );\n" + " $this->form->addQuickField('Biometria', $senha_biometria, '100%' );\n" + " $this->form->addQuickField('Data Inicio Pausa', $data_inicio_pausa, '50%' );\n" + " $this->form->addQuickField('Data Fim Pausa', $data_fim_pausa, '50%' );\n" + " $this->form->addQuickField('Data Nasc Fundacao', $data_nasc_fundacao, '50%' );\n" + " $this->form->addQuickField('Mãe', $mae, '100%' , new TRequiredValidator);\n" + " $this->form->addQuickField('Pai', $pai, '100%' );\n" + " $this->form->addQuickField('Nascimento', $data_nascimento, '50%' , new TRequiredValidator);\n" + " $this->form->addQuickField('Rg', $rg, '100%' );\n" + " $this->form->addQuickField('Orgão Expedidor', $sigla_orgao_expedidor, '100%' );\n" + " $this->form->addQuickField('Conf Pessoa Tipo Id', $conf_pessoa_tipo_id, '50%' );\n" + " $this->form->addQuickField('Conf Pessoa Tipo Documento Id', $conf_pessoa_tipo_documento_id, '50%' );\n" + " $this->form->addQuickField('Conf Geral Status Id', $conf_geral_status_id, '50%' );\n" + " $this->form->addQuickField('System User Id', $system_user_id, '50%' );\n" + " $this->form->addQuickField('Conf End Cidades Id', $conf_end_cidades_id, '50%' );\n" + " $this->form->addQuickField('Conf End Estados Id', $conf_end_estados_id, '50%' );\n" + " $this->form->addQuickField('Conf Sexos Id', $conf_sexos_id, '50%' );"; final String subst = "\\t$this->form->addFields(\\n\\t\\t[ new TLabel($1) ]\\n\\t\\t,[$2]\\n\\t);\\n\\t$2->setSize($3);\\n"; final Pattern pattern = Pattern.compile(regex, Pattern.MULTILINE); final Matcher matcher = pattern.matcher(string); // The substituted value will be contained in the result variable final String result = matcher.replaceAll(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