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isset vs is_null

Better Barracuda answered on December 2, 2022 Popularity 7/10 Helpfulness 6/10

answer isset vs is_null

isset vs is_null

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$a - variable with not null value (e.g. TRUE)
$b - variable with null value. `$b = null;`
$c - not declared variable
$d - variable with value that cast to FALSE (e.g. empty string, FALSE or empty array)
$e - variable declared, but without any value assigned
$a->a - declared, but not assigned object property. (`public $a;`)
A::$a - declared, but not assigned static class property.

         |   $a  |   $b  |   $c  |   $d  |   $e  | $a->a | A::$a |
---------+-------+-------+-------+-------+-------+-------+-------+
is_null()| FALSE | TRUE  |TRUE*W | FALSE | TRUE*W| TRUE  | TRUE  |
---------+-------+-------+-------+-------+-------+-------+-------+
isset()  | TRUE  | FALSE | FALSE | TRUE  | FALSE | FALSE | FALSE |
---------+-------+-------+-------+-------+-------+-------+-------+
empty()  | FALSE | TRUE  | TRUE  | TRUE  | TRUE  | TRUE  | TRUE  |
---------+-------+-------+-------+-------+-------+-------+-------+
null === | FALSE | TRUE  |TRUE*W | FALSE | TRUE*W| TRUE  | TRUE  |
---------+-------+-------+-------+-------+-------+-------+-------+
null ==  | FALSE | TRUE  |TRUE*W | TRUE  | TRUE*W| TRUE  | TRUE  |
---------+-------+-------+-------+-------+-------+-------+-------+

TRUE*W - function return TRUE, but same time emits WARNING.

Popularity 7/10 Helpfulness 6/10 Language whatever

Source: stackoverflow.com

Tags: isset whatever

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Contributed on Dec 02 2022

Better Barracuda

0 Answers Avg Quality 2/10

isset vs is_null

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