diffrenece between $a=''; and $a=NULL; in php
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  <p><strong>Possible Duplicate:</strong><br>
  <a href="http://stackoverflow.com/questions/624922/in-php-what-is-the-differences-between-null-and-setting-a-string-to-equal-2-sing">In PHP, what is the differences between NULL and setting a string to equal 2 single quotes.</a>  </p>
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<p>What does $a=''; indicates in php</p>

<p>and how $a=''; is different than $=NULL:</p>
