As a qualified PHP programmer, you must know some basic knowledge, such as the difference between 0 and null. Regarding this difference, the following is a simple analysis through several examples. The truth can only be understood. , indescribable, readers can slowly experience it themselves.
$test=0;
if($test==''){
echo '
In php, 0 means empty'; //Output
}
if($test===''){
echo '
In php, 0 means empty'; //Not output
}
if($test==NULL){
echo '
In php, 0 means empty'; //Output
}
if($test===NULL){
echo '
In php, 0 means empty'; //Not output
}
if($test==false){
echo '
In php, 0 means empty'; //Output
}
if($test===false){
echo '
In php, 0 means empty'; //Not output
}
?>