title: Char array in C
body: <p>I define a function</p>
  
  <pre><code>void add(char *key, char *value) {
  }
  </code></pre>
  
  <p>And I have a string </p>
  
  <pre><code>char * message = "hello world"
  </code></pre>
  
  <p>I want to call add("hello", "world"), so I write </p>
  
  <pre><code>add(message[0,4], message[6, 10]) 
  </code></pre>
  
  <p>It does not work, I am refused with the "char *" and "char array", who can explain for me? </p>