unset.offset

Code example

<?php declare(strict_types = 1);

function doFoo(): void
{
	$scalar = 3;
	unset($scalar['a']);
}

Why is it reported?

The unset() call attempts to remove an array offset from a type that either does not support offset access or does not have the specified offset. This indicates a logic error -- the variable is not the array that was expected, or the offset does not exist on the given type.

In the example above, $scalar is an int, which does not support offset access. Attempting to unset an offset on it is meaningless.

How to fix it

Make sure unset() is called on a variable that supports offset access and has the given offset:

 <?php declare(strict_types = 1);

 function doFoo(): void
 {
-	$scalar = 3;
-	unset($scalar['a']);
+	$data = ['a' => 1, 'b' => 2];
+	unset($data['a']);
 }

Or verify the type of the variable before unsetting:

 <?php declare(strict_types = 1);

-/** @param iterable<int, int> $iterable */
-function doBar(iterable $iterable): void
+/** @param array<int, int> $data */
+function doBar(array $data): void
 {
-	unset($iterable['string']);
+	unset($data[0]);
 }