What does null mean? Analysis of the difference between unset and null when deleting a variable in PHP

The first method: $varname =null
Second method: Unset ($varname)
Both of these methods can delete variables, but the results are slightly different.
Code:

Copy the Code code as follows:

$a = Array (
' A ' = ' a ',
' B ' = ' B '
);
$b = Array (
' A ' = ' a ',
' B ' = ' B '
);
$a [' b '] = null;
unset ($b [' B ']);
Print ('

Print ('


Print ('

');
?>

Results:

Copy the Code code as follows:

Array
(
[A] = a
[b] = =
)
Array
(
[A] = a
)

The above explains what NULL means when you delete a variable in PHP, the difference between unset and NULL, including the content of what NULL means, is helpful to a friend who is interested in PHP tutorials.

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