check if numbers have the same sign
<p>I came across this:
<a href="http://stackoverflow.com/questions/66882/simplest-way-to-check-if-two-integers-have-same-sign">http://stackoverflow.com/questions/66882/simplest-way-to-check-if-two-integers-have-same-sign</a></p>

<p>How can this be extended to more than two numbers (not necessarily integers)? Say, check if 4 numbers have the same sign (+ve or -ve).</p>

<p>I don't want to use bit operations as far as possible ... only logical conditions.</p>

<p>Thanks.</p>
