How to convert byte array to integer in php?

Question

I have seen a code that converts integer into byte array. Below is the code on How to convert integer to byte array in php 3 (How to convert integer to byte array in php):

<?php

$i = 123456;
$ar = unpack("C*", pack("L", $i));

print_r($ar);
?>

The above code will output:

//output:
Array
(
   [1] => 64
   [2] => 226
   [3] => 1
   [4] => 0
)

But my problem right now is how to reverse this process. Meaning converting from byte array into integer. In the case above, the output will be 123456

Can anybody help me with this. I would be a great help. Thanks ahead.

Answer 1

Why not treat it like the math problem it is?

$i = ($ar[3]<<24) + ($ar[2]<<16) + ($ar[1]<<8) + $ar[0];