title: c# dictionary How to add multiple values for single key?
body: <p>I have created dictionary object </p>
  
  <pre><code>Dictionary&lt;string, List&lt;string&gt;&gt; dictionary =
      new Dictionary&lt;string,List&lt;string&gt;&gt;();
  </code></pre>
  
  <p>I want to add string values to the list of string for a given single key.
  If the key doesn't already exists then I have to add a new key. <code>List&lt;string&gt;</code> is not predefined, I mean I didn't create any list object and then supplied to <code>dictionary.Add("key",Listname)</code>. How to create dynamically this list object in <code>dictionary.Add("key",Listname)</code> and then add strings to this list. If I have to add 100 keys then do I have to create 100 lists before executing <code>dictionary.Add</code> instruction and also do I have to pedefine the contents of this lists ?</p>
  
  <p>Thank you. </p>