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PHP NULL
Definition and Usage
In PHP, a variable with no value is said to be of null data type. Such a variable has a value defined as NULL. A variable can be explicitly assigned NULL or its value been set to null by using unset() function.
Syntax
$var=NULL;
It is possible to cast variable of other type to null, although casting null to other type has been deprecated from PHP 7.2. In earlier versions, casting was done using (unset)$var syntax
Following example shows how to assign NULL to a variable
Example
<?php $var=NULL; var_dump($var); ?>
Output
This will produce following result −
NULL
Following example performs null variable to other primary variables
Example
<?php $var = NULL; var_dump( (int) $var); var_dump((float)$var); var_dump((bool) $var) ; var_dump( (boolean) $var); ?>
Output
This will produce following result −
int(0) float(0) bool(false) bool(false)
Updated on: 19-Sep-2020
5K+ Views
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