title: How should work with arrays of string in c
body: <p>I want to use an array of string  the same as this:</p>
  
  <pre><code>char arr[][20] = {"username1", "username2"};
  </code></pre>
  
  <p>after i have not problem to get values, for example :</p>
  
  <pre><code>printf("%s", arr[0]); // for "username1"
  </code></pre>
  
  <p>i have problem to insert new string to this array, something like this!? :</p>
  
  <pre><code>arr[2] = "username3"; // or sprintf(arr[2], "%s", "username3");
  </code></pre>