Understanding NULL in PHP: Handling Absence of Value

Null is a special data type which can have only one value: NULL.

A variable of data type NULL is a variable that has no value assigned to it.

Tip: If a variable is created without a value, it is automatically assigned a value of NULL.

Variables can also be emptied by setting the value to NULL:

Syntax:

<span class="pln">

</span><span class="pun">&lt;?</span><span class="pln">php
$x </span><span class="pun">=</span><span class="pln"> </span><span class="str">"Hello world!"</span><span class="pun">;</span><span class="pln">
$x </span><span class="pun">=</span><span class="pln"> </span><span class="kwd">null</span><span class="pun">;</span><span class="pln">
var_dump</span><span class="pun">(</span><span class="pln">$x</span><span class="pun">);</span><span class="pln">
</span><span class="pun">?&gt;</span><span class="pln">

</span>