Regex.Matches, quote

In C# programs, strings sometimes have quoted values—it is often useful to extract these values. This helps us parse text or code such as SQL statements.

Program uses

We can use Regex for an efficient and simple way to do this. We handle quoted values with Regex. Some syntax, like escaped values, are harder to support.

Example

We match values within quotes using Regex.Matches. To use Regex.Matches, pass it a pattern—this specifies the group you are capturing. Our group here is surrounded by single quotes.

using System;
using System.Text.RegularExpressions;

// Part 1: the input string.
string line = "INSERT INTO country VALUES ('BH','BAHRAIN','Bahrain','BHR','048');";

// Part 2: match all quoted fields.
MatchCollection col = Regex.Matches(line, @"'(.*?)'");

// Part 3: copy groups to a string array.
string[] fields = new string[col.Count];
for (int i = 0; i < fields.Length; i++)
{
    fields[i] = col[i].Groups[1].Value; // (Index 1 is the first group)
}

// Part 4: display the fields.
foreach (string field in fields)
{
    Console.WriteLine(field);
}
BH
BAHRAIN
Bahrain
BHR
048

Performance

Regular expressions do not result in optimal execution time. Therefore, in performance-critical situations, you will want a more complex parser.

A summary

We extracted quoted values from an input string using Regex.Matches. This style of code is sometimes useful to developers working with regular expressions.