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C# Regex.Split, Get Numbers From StringUse Regex.Split and the non-digit Regex metacharacter to get numbers from a string.
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Regex.Split, numbers. Regex.Split can extract numbers from strings. We get all the numbers that are found in a string. Ideal here is the Regex.Split method with a delimiter code.

Method notes. We describe an effective way to get all positive ints. For floating point numbers, or negative numbers, another solution will be needed.

Input and output. Let us first consider the input and output of our Regex.Split call. We want to extract digit sequences of 1 or more chars. This leaves us with numbers (in a string array).

Array

Input and output:
ABC 4: 3XYZ 10 Results = 4 3 10

Example program. The const input string has 4 numbers in it: they are one or two digits long. To acquire the numbers, we use the format string @"\D+" in the Regex.Split method.

Regex.Split

Pattern The pattern "\D+" indicates that we want to use any number of one or more non-digit characters as a delimiter.

Using Please notice how the System.Text.RegularExpressions namespace is included.

Regex

Return The Regex.Split method will return the numbers in string form. The result array may also contain empty strings.

Info To avoid parsing errors, we use the string.IsNullOrEmpty method. Finally, we invoke the int.Parse method to get integers.

IsNullOrEmpty, IsNullOrWhiteSpace

int.Parse

C# program that extracts numbers with Regex.Split
using System; using System.Text.RegularExpressions; class Program { static void Main() { const string input = "ABC 4: 3XYZ 10"; // Split on one or more non-digit characters. string[] numbers = Regex.Split(input, @"\D+"); foreach (string value in numbers) { if (!string.IsNullOrEmpty(value)) { int i = int.Parse(value); Console.WriteLine("Number: {0}", i); } } } }
Number: 4 Number: 3 Number: 10

Pattern details:
\D Non-digit char. + 1 or more of char.

Notes, pattern. For handling numbers in regular expressions, the "\d" and "\D" codes are important. The lowercase "d" means digit character. The uppercase means non-digit char.

A summary. We extracted integers inside a string. And we converted the results to ints. The Regex.Split method is useful for this purpose. It allows flexible, complex delimiters.

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