How to replace values in existing string in C#

you can pass the values in variables which you want to replace and of which one

            char a;
            char b;
            a = '2';
            b = '6';
            char c;
            char d;
            c = '5';
            d = '7';
Newstr= OldString.Replace(a, b).Replace(c, d);

If I were you, I would do that this way :

string oldString = "A=3;B=2;C=5";

Separate each part :

string[] parts = oldString.Split(";");
// You will then have
// parts[0] == "A=3"
// parts[1] == "B=2"
// parts[2] == "C=5"

Use a Dictionary<string, int> to store letters and values :

var dic = new Dictionary<string, int>();
foreach (string part in parts) {
   string[] sep = part.Split("=");
   dic.Add(sep[0], int.Parse(sep[1]);
}

Replace the parts you need to as per your requirements

dic["B"] = 6;
dic["C"] = 7;

Put everything back together

string[] newParts = new string[parts.Length];
int i = 0;
foreach (var kvp in dic) {
   string val = string.Format("{0}={1}", kvp.Key, kvp.Value);
   newParts[i++] = val;
}
string newString = string.Join(newParts, ";");

That should get you near what you want.

Hope this helps. Regards.

Hi All,

But

OldString

and newString created dynamically then what i can do ??