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What Is the is_null method in PHP?
The is_null method can be used to check if a variable is NULL or not.
Syntax
is_null(mixed ＄value): bool
The is_null method returns true if the passed value is NULL. Otherwise, it returns false.
Code
<?phpprintIsNull($test); // undefined variable is NULL$test = NULL;printIsNull($test);$test = 0;printIsNull($test);$test = 'NULL';printIsNull($test);function printIsNull($test){echo "The Value is: ";var_dump($test);echo "Is null: ";var_dump(is_null($test));echo "---------\n\n";}?>
Explanation
In the code above:
-
We use the
is_nullmethod to check if a variable isNULLor not. -
For the undeclared variable and for the value
NULL, theis_nullmethod returnstrue. -
But for the values
0(int)and'NULL'(string), theis_nullmethod returnsfalsebecause they are notNULLvalues.
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