The is_null Function
The is_null function checks if a variable contains the value null. Returns true if the variable's value is equal to null, and false otherwise.
Syntax
is_null(mixed $value): bool
Example
Let's check several values for null:
<?php
$var1 = null;
$var2 = 'abc';
$var3 = 0;
var_dump(is_null($var1));
var_dump(is_null($var2));
var_dump(is_null($var3));
?>
Code execution result:
true
false
false
Example
Let's check an uninitialized variable:
<?php
var_dump(is_null($undefinedVar));
?>
Code execution result:
true
Example
Comparison with other data types:
<?php
$arr = [1, null, 3];
var_dump(is_null($arr[1]));
?>
Code execution result:
true
