How to count the consecutive duplicate values in an array?

Question

I have an array like this:

$arr = array(1, 1, 1, 2, 2, 3, 3, 1, 1, 2, 2, 3);

I found the function array_count_values(), but it will group all of the same values and count the occurrences without respecting breaks in the consecutive sequences.

$result[1] = 5
$result[2] = 4
$result[3] = 3

How can I group each set of consecutive values and count the length of each sequence? Notice there are two sets of sequences for the numbers 1, 2, and 3.

The data that I expect to generate needs to resemble this:

[1] = 3;
[2] = 2;
[3] = 2;
[1] = 2;
[2] = 2;
[3] = 1;

Answer 1

What about PHP's array_count_values function?

<?php
$array = array(1, "hello", 1, "world", "hello");
print_r(array_count_values($array));
?>

output:

Array
(
    [1] => 2
    [hello] => 2
    [world] => 1
)