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
No Match

/
/
gi

Test String

Substitution

Processing...

Code Generator

Language

Generated Code

using System; using System.Text.RegularExpressions; public class Example { public static void Main() { string pattern = @"(\(\s?function+.formula.*\{\s?)([\w|\.]+\s?=[^\}]*)(\s?\}\s?\)\s?\(\s?\)\s?;)"; string substitution = @"Calcular('$2'); "; string input = @" (function Formula(x){ ListaOP.FormaPActiva.RemanenteACancelar = ListaOP.OPActiva.TotalesCliente.Total - ListaOP.OPActiva.MontoAcumuladoFormasPago; })(variableX); (function Formula() { ListaOP.FormaPActiva.ImporteACancelar = ListaOP.FormaPActiva.RemanenteACancelar; })(); (function formula(){ a=b; })(); if (!v.Parametros.AfectarGastoEnvioRecargoFinanciero && ListaOP.OPActiva.MontoCanceladoContado < v.GastoEnvio + v.GastoEnvioImpuestoCliente) { (function formula() { ListaOP.FormaPActiva.RemanenteACancelar = ListaOP.FormaPActiva.RemanenteACancelar - v.GastoEnvio - v.GastoEnvioImpuestoCliente; })(); } var c = function(){ }; (function Formula() { ListaOP.FormaPActiva.ImporteFinanciamientoTotal = ListaOP.FormaPActiva.RemanenteACancelar * (ListaOP.FormaPActiva.CoeficienteFinanciacion - 1); })(); (function Formula() { ListaOP.FormaPActiva.ImporteACancelar = ListaOP.FormaPActiva.ImporteACancelar + ListaOP.FormaPActiva.ImporteFinanciamientoTotal; })(); (function Formula(x) { ListaOP.FormaPActiva.RemanenteACancelar = ListaOP.FormaPActiva.ImporteACancelar; })(10);"; RegexOptions options = RegexOptions.IgnoreCase; Regex regex = new Regex(pattern, options); string result = regex.Replace(input, substitution); } }

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 C#, please visit: https://msdn.microsoft.com/en-us/library/system.text.regularexpressions.regex(v=vs.110).aspx