title: Replace method is not replacing characters in a string
body: <p>I have a method that should remove repeated characters in a string and replace j character by i character but the replacement is not working !! is there any wrong statement in my codes?  </p>
  
  <pre><code>public string filter(string key)
          {
              string answer = "";
              string keyEdit = key;
              bool found = keyEdit.Contains('j');
              if (found)
              {
                  keyEdit.Replace('j', 'i'); // Replace j character by i character 
              }
              answer = new string(keyEdit.Distinct().ToArray()); // Removing duplicate characters
              return answer;
          }
  </code></pre>