Float handling changes since 8.0 - on purpose?

[Guite]

Description

The following code:

<?php
$a = 676.71;
$b = 108.05;

var_dump($a - $b);

Resulted in this output:

float(568.6600000000001)

But I expected this output instead:

float(568.66)

This BC break is not documented at https://www.php.net/manual/en/migration80.incompatible.php

Hence, I'd consider this a bug.

PHP Version

PHP 8.*

Operating System

any

[heiglandreas]

Quoting from php.net/manual/en/migration80.incompatible.php:

var_dump() and debug_zval_dump() will now print floating-point numbers using serialize_precision rather than precision. In a default configuration, this means that floating-point numbers are now printed with full accuracy by these debugging functions.

This is not a bug.

Besides: As per https://www.php.net/float the warning is rather clear.

So never trust floating number results to the last digit, and do not compare floating point numbers directly for equality. If higher precision is necessary, the arbitrary precision math functions and gmp functions are available.

[Guite]

Okay understood. Closing then.