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<!DOCTYPE html> <html> <body> <?php // A variable that does not exist if(empty($x)) { echo '$x does not exist<br>'; } // An empty integer if(empty(0)) { echo '0 is empty<br>'; } // An empty float if(empty(0.0)) { echo '0.0 is empty<br>'; } // An empty string if(empty("")) { echo '"" is an empty string<br>'; } // null if(empty(null)) { echo 'null is empty<br>'; } // A value that is not empty if(empty('A')) { echo '"A" is empty<br>'; } else { echo '"A" is not empty<br>'; } ?> </body> </html>
$x does not exist
0 is empty
0.0 is empty
"" is an empty string
null is empty
"A" is not empty