Changing specific value in a dictionary while finding it by it's key

Question

I have a dictionary called users, i want to modify/change a specific value withing dictionary while doing that i try to find that value by searching through keys.. i dont know how to change that value into something else :) I'm not sure if its even possible but wonder if its possible what is the syntax.. ty in advance. o/

txtRecoveryCustomerId.Text is a param that is written by user to start recovery process. All is simulation im just trying to learn :)

Dictionary<string, string> users = new Dictionary<string, string>();
users.Add("12345", "666");
 foreach (var item in users)
            {
                if (item.Key.Contains(txtRecoveryCustomerId.Text))
                {
                   
                    //item.Replace(Convert.ToChar(users.Values), Convert.ToChar(txtPasswordChange.Text));
                }
            }

Answer 1

You really need to perform two operations, neither of which requires a loop.

1. Ensure the user exists (aka: the dictionary contains the key)
2. Set the value stored by that key

You can use the following code to accomplish this:

Dictionary<string, string> users = new Dictionary<string, string>();
users.Add("12345", "666");

// reset password if the user exists
if (users.ContainsKey(txtRecoveryCustomerId.Text))
    users[txtRecoveryCustomerId.Text] = txtPasswordChange.Text;

Answer 2

try this

   foreach (var item in users)
   if (item.Key.Contains(txtRecoveryCustomerId.Text))
  {
    users[item.Key] = txtPasswordChange.Text;
   break;
  }