if I have a string along the lines of: "user:jim;id:23;group:49st;" how can I replace the group code (49st) with something else, so that it shows: "user:jim;id=23;group:76pm;"
sorry if the question is easy but I haven't found a specific answer, just cases different than mine.
You can use the index of "group" like this
string s = "user:jim;id:23;group:49st;";
string newS = s.Substring(0,s.IndexOf("group:") + 6);
string restOfS = s.IndexOf(";",s.IndexOf("group:") + 6) + 1 == s.Length
? ""
: s.Substring(s.IndexOf(";",s.IndexOf("group:") + 6) + 1);
newS += "76pm;";
s = newS + restOfS;
The line with the s = criteria ? true : false is essentially an if but it is put onto one line using a ternary operator.
Alternatively, if you know what text is there already and what it should be replaced with, you can just use a Replace
s = s.Replace("49st","76pm");
As an added precaution, if you are not always going to have this "group:" part in the string, to avoid errors put this inside an if which checks first
if(s.Contains("group:"))
{
//Code
}
Find the match using regex and replace it with new value in original string as mentioned below:
string str = "user:jim;id=23;group:49st;";
var match = Regex.Match(str, "group:.*;").ToString();
var newGroup = "group:76pm;";
str = str.Replace(match, newGroup);
This solution should work no matter where the group appears in the string:
string input = "user:jim;id:23;group:49st;";
string newGroup = "76pm";
string output = Regex.Replace(input, "(group:)([^;]*)", "${1}"+newGroup);
Here is a very generic method for splitting your input, changing items, then rejoining items to a string. It is not meant for single replacement in your example, but is meant to show how to split and join items in string.
I used Regex to split the items and then put results into a dictionary.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
namespace ConsoleApplication1
{
class Program
{
static void Main(string[] args)
{
string pattern = "(?'name'[^:]):(?'value'.*)";
string input = "user:jim;id:23;group:49st";
Dictionary<string,string> dict = input.Split(new char[] { ';' }, StringSplitOptions.RemoveEmptyEntries).Select(x => new
{
name = Regex.Match(x, pattern).Groups["name"].Value,
value = Regex.Match(x, pattern).Groups["value"].Value
}).GroupBy(x => x.name, y => y.value)
.ToDictionary(x => x.Key, y => y.FirstOrDefault());
dict["group"] = "76pm";
string output = string.Join(";",dict.AsEnumerable().Select(x => string.Join(":", new string[] {x.Key, x.Value})).ToArray());
}
}
}
That is just one way to do it. I hope it will help you.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace stringi
{
class Program
{
static void Main(string[] args)
{
//this is your original string
string s = "user:jim;id:23;group:49st";
//string with replace characters
string s2 = "76pm";
//convert string to char array so you can rewrite character
char[] c = s.ToCharArray(0, s.Length);
//asign characters to right place
c[21] = s2[0];
c[22] = s2[1];
c[23] = s2[2];
c[24] = s2[3];
//this is your new string
string new_s = new string(c);
//output your new string
Console.WriteLine(new_s);
Console.ReadLine();
}
}
}
string a = "user:jim;id:23;group:49st";
string b = a.Replace("49st", "76pm");
Console.Write(b);
string b = a.Replace("group:49st", "group:76pm");
49stto76pmorgroup:xtogroup:76pm?