Differences between unset () and null when deleting variables in PHP _ PHP Tutorial

Differences between unset () and null when deleting variables in PHP. The first method is $ varnamenull. The second method is unset ($ varname). both methods can delete variables, but the results are slightly different. Code: Copy the code as follows :? Php $ a first method: $ varname = null
Method 2: unset ($ varname)
Both methods can delete variables, but the results are slightly different.
Code:

The code is as follows:

$ A = array (
'A' => 'A ',
'B' => 'B'
);
$ B = array (
'A' => 'A ',
'B' => 'B'
);
$ A ['B'] = null;
Unset ($ B ['B']);
Print ('

'); 
print_r($a); 
print('
'); 
print_r($b); 
print('

');
?>

Result:

The code is as follows:

Array
(
[A] =>
[B] =>
)
Array
(
[A] =>
)

Except the second method: unset ($ varname) both methods can delete variables, but the results are slightly different. Code: The code is as follows :? Php $...