How to define null querystring in php?
<p>I am newbie in php,please guide me ^.^</p>

<p>I want to define the querystring pass with null or with value like eg(wrong code):</p>

<p>with 2 query string url:</p>

<p>localhost/example.php?access=abc&amp;value1=abc</p>

<p>with 3 query string url:</p>

<p>localhost/example.php?access=abc&amp;value1=abc&amp;value2=efg</p>

<pre><code>if(isset($_GET['value2'])){     
    //if value2 is null then condition
}
else{
    //if define value2 then condition
}
</code></pre>
