title: 'Ì' or '\0' in visual studio is null
body: <p>i write a code in visual studio and in algorithm seem to be right but 
  but won't work! I don't know put <code>Ì</code> (-52) or <code>\0</code> for my code</p>
  
  <pre><code>void strcat(char *destin, char *source){
      while (*destin != '\0')
          destin++;
      while (*source != '\0')
      {
          *destin = *source;
          destin++;
          source++;
      }
      *destin = '\0';
  }
  
  main(){
      char s1[100];
      strcat(s1, "salam");
      strcat(s1, "hello");
      strcat(s1, "ahlan");
      strcat(s1, "keifolhal");
      printf("%s", s1);
      return 0;
  }
  </code></pre>