Storing a reversed string
<p>I Want to store the reversed string a in b without any function.</p>

<blockquote>
  <p>public static void main(String args[])
    {</p>

<pre><code>  BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
  String a=br.readLine();
  String b;
  for(int x=0,y=a.length()-1;x&lt;a.length();x++,y--)
  {
             b.charAt(x)=a.charAt(y);
  }
</code></pre>
</blockquote>

<p>But I get this error :</p>

<blockquote>
<pre><code>                   b.charAt(x)=a.charAt(y);
                           ^
</code></pre>
  
  <p>required: variable</p>
  
  <p>found:    value</p>
  
  <p>1 error</p>
</blockquote>

<p>Can you explain it and help me fix it ?</p>
