How to remove particular div from a String(string having html code)?

Quote:

In computing, a regular expression is a specific pattern that provides concise and flexible means to "match" (specify and recognize) strings of text, such as particular characters, words, or patterns of characters. Common abbreviations for "regular expression" include regex and regexp.

using System;
using System.Text.RegularExpressions;

class Program
{
    static void Main()
    {
        // This is the input string we are replacing parts from.
        string input = "<div id="header"></div> <div id="body"></div> <div id="footer"></div>";
    
        // Use Regex.Replace to replace the pattern in the input.
        // Here you enter your pattern with the div or anything else you wish to remove.
        string RegexPattern = "body";  
        string output = Regex.Replace(input, RegexPattern , "");
    
        // Write the output.
        Console.WriteLine(input);
        Console.WriteLine(output);
    }
}