CharAt gives "Cannot find symbol" error
<p>I recently start studying JAVA, and I find this code:</p>

<pre><code>public class Dublicate{
   public static void main(String[] args){
      int r=0;
      for(int i=0;i&lt;(args[0]).length();i++){
         char ch=args[0].CharAt(i);
         r=r*10+ch-'0';
      }
      System.out.println(r);
    }
} 
</code></pre>

<p>I don't really confident that this code will work properly, I don't confident in 
<code>args[0]</code>, but this code don't what to compile:</p>

<pre><code>Dublicate.java:6: cannot find symbol  
symbol  : method CharAt(int)  
location: class java.lang.String  
            char ch=a.CharAt(i);  
                     ^  
1 error
</code></pre>

<p><strong>How I can solve this problem?</strong></p>

<p>P.S. Also if I write:</p>

<pre><code>int i=4;
String a = "argsas";
char ch=a.CharAt(i); 
</code></pre>

<p>I also get Error:</p>

<pre><code>Dublicate.java:5: cannot find symbol  
symbol  : method CharAt(int)  
location: class java.lang.String  
             char ch=a.CharAt(i);  
                      ^  
1 error  
</code></pre>

<p><strong>Update:</strong>
Yeah, lovercase works thank you all!!!</p>
