significance of && in if()
<p>I would like to know is there any difference in performance between these two codes.</p>

<pre><code>String sample="hello";
    if(sample!=null)
    {
       if(!sample.equals(""))
        {
            // some code in here
         }
    }
</code></pre>

<p>or</p>

<pre><code>String sample="hello";
    if(sample!=null &amp;&amp; !sample.equals(""))
    {

            // some code in here
    }
</code></pre>

<p>As far as i have understood, in the first code, if sample is not null then only it will go in to the block. same is the case with 2nd piece of code.
What i would like to know is what is the difference in performance or better coding standards and why?</p>
