作为一个合格的php程序员，一些基础知识是必须要知道的，例如0和空的区别，关于这个区别，下面就通过几个实例进行简单的分析，其中的道理，只可意会，不可言传，读者可以自己去慢慢体会了。
<?php $test=0;
if($test==''){
echo '<br />在php中，0即为空'; //被输出
}
if($test===''){
echo '<br>在php中，0即为空'; //不被输出
}
if($test==NULL){
echo '<br>在php中，0即为空'; //被输出
}
if($test===NULL){
echo '<br>在php中，0即为空'; //不被输出
}
if($test==false){
echo '<br>在php中，0即为空'; //被输出
}
if($test===false){
echo '<br>在php中，0即为空'; //不被输出
}
?>
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