What is the Difference Between unset and null in PHP ?

In PHP, unset and null are used to handle variables differently. unset is a language construct used to destroy a variable, while null is a special value representing a variable with no value assigned to it.

Syntax

unset($variable);
$variable = null;

Difference Between unset and null

unset()	null
Destroys a variable and frees up memory	Assigns a null value to a variable
Makes a variable undefined	Indicates that a variable has no value assigned
Cannot be used with non-variable expressions	Can be assigned to any variable or expression

Features

• Variable Destruction: unset is used to completely remove a variable from memory, freeing up resources.
• Null Assignment: Assigning null to a variable explicitly sets it to a null value, indicating the absence of a value.
• Memory Management: unset can be useful for managing memory usage in PHP scripts by freeing up memory occupied by unused variables.

Example:

$var = "Hello";
unset($var);
// $var is now undefined

$var2 = null;
// $var2 is explicitly assigned a null value