Why is this call to strstr not returning false? : <p>I've stumbled upon an issue with <a href="https://secure.php.net/manual/en/function.strstr.php" rel="noreferrer">strstr</a> in an old legacy codebase. There's lot of code, but basically the test case would come down to this:</p>

<pre><code>$value = 2660;
$link = 'affiliateid=1449&amp;zoneid=6011&amp;placement_id=11736&amp;publisher_id=1449&amp;period_preset=yesterday&amp;period_start=2017-03-27&amp;period_end=2017-03-27';

var_dump(strstr($link, $value));
</code></pre>

<p>I would expect this to return <code>false</code> since "2660" is not in the string however it returns <code>d=1449&amp;zoneid=6011&amp;placement_id=11736&amp;publisher_id=1449&amp;period_preset=yesterday&amp;period_start=2017-03-27&amp;period_end=2017-03-27</code>.</p>

<p>I realise that <code>$value</code> should be a string but still I don't understand why it's not casted to a string by PHP and why it's finding this number in the link.</p>

<p>Actually, if I try with <code>$value = '2660';</code> it returns <code>false</code> as expected.</p>

<p>Any idea what's happening?</p>
