PHP's unsigned integer on 32 bit and 64 bit platform

Question

Here is the code:

echo sprintf('%u',-123);

And this is the output on 32 bit platform:

4294967173

but on 64 bit:

18446744073709551493

How to make it the same ?Say,the int(10) unsigned

Answer 1

echo sprintf('-%u',abs(-123));

or

$n = -123;
echo sprintf("%s%u", $n < 0 ? "-":"", abs($n));

Though if you actually want to see the two's complement unsigned value of a negative number restricted to 32 bits just do:

echo sprintf("%u", $n & 0xffffffff);

And that will print 4294967173 on all systems.

Answer 2

Check out my answer to this question for some ideas - in a nutshell, you can check the value of the PHP_INT_SIZE constant to perform different processing on a 64bit platform.