The test _php tutorial for parsing empty is_null and isset in PHP

The code is as follows:
Copy CodeThe code is as follows:
$a;
$b = false;
$c = ";
$d = 0;
$e = null;
$f = Array ();

the first is the empty var_dump output:
Boolean true
Boolean true
Boolean true
Boolean true
Boolean true
Boolean true

Then the output of the Is_null:
Boolean true
Boolean false
Boolean false
Boolean false
Boolean true
Boolean false

Finally, the output of the isset:
Boolean false
Boolean true
Boolean true
Boolean true
Boolean false
Boolean true
This shows that empty () can be used to determine whether all data types are empty or false, and is_null is basically the same as isset, and can only be used to determine if null and undefined.

http://www.bkjia.com/PHPjc/327918.html www.bkjia.com true http://www.bkjia.com/PHPjc/327918.html techarticle the code is as follows: Copy the code as follows: PHP $a; $b = false; $c = "; $d = 0; $e = null; $f = Array (); First empty Var_dump output: Boolean true bool Ean true Boolean true bool ...

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