Replace & Split in C#

Regexes as text surgery: split on patterns, replace by function.

using System.Text.RegularExpressions;

var messy = "one,two;three  four";
var parts = Regex.Split(messy, @"[,;\s]+");
Console.WriteLine(string.Join("|", parts));

// Replace can compute each substitution from its match
var text = "call 555-0100 or 555-0199";
var masked = Regex.Replace(text, @"\d{3}-\d{4}",
                           m => new string('*', m.Value.Length));
Console.WriteLine(masked);

How it works

1. Regex.Split cuts on any run of separators in one pass.
2. Replace accepts a lambda, computing each substitution.
3. The mask keeps each match's length — data-dependent output.

Keywords and builtins used here

• new
• string
• using
• var

The run, in numbers

Lines

11

Characters to type

373

Tokens

73

Three-star pace

85 tpm

At the three-star pace of 85 tokens a minute, this run takes about 52 seconds.

Type this snippet

Step 2 of 3 in Regular expressions, step 2 of 17 in The .NET library.

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