Static Regex

A static Regex helps performance. It can be used throughout methods in the C# program. This reduces allocations and can simplify programs.

Single-instance Regex

A static Regex is essentially a single-instance regular expression. Static regular expressions have clear performance advantages.

To start, we demonstrate the use of a static Regex. You can use a static variable initializer at the class level to instantiate the regular expression with the new operator.

using System;
using System.Text.RegularExpressions;

class Program
{
    static Regex _rWord = new Regex(@"R\w*");

    static void Main()
    {
        // Use the input string.
        // ... Then try to match the first word starting with capital R.
        string value = "This is a simple /string/ for Regex.";
        Match match = _rWord.Match(value);
        Console.WriteLine(match.Value);
    }
}
Regex

Performance

Static regular expressions show a performance advantage. Static fields do not have an instance expression, so resolving the location of their memory storage is slightly faster.

Performance, continued

Regular expressions are not an ideal solution for performance. They can be sped up with considerations of their allocation patterns, as with the static modifier.

A summary

We implemented a static regular expression. This can improve performance by enhancing the access patterns to the regular expression and restricting heap allocations.