Non-strict comparation of object and scalar value

Description

The following code:

<?php

class Foo
{
    public $bar = 1;
}

$o = new Foo();
$s = '1';
$b = true;
$i = 1;
$f = 1.0;

var_dump($o == $s);
var_dump($o == $b);
var_dump($o == $i);
var_dump($o == $f);

Resulted in this output:

bool(false)
bool(true)

Notice: Object of class Foo could not be converted to int in /in/mreGe on line 16
bool(true)

Notice: Object of class Foo could not be converted to float in /in/mreGe on line 17
bool(true)

But I expected this output instead:

bool(true)
bool(true)
bool(true)
bool(true)

or

Notice: Object of class Foo could not be converted to string in /in/mreGe on line 14
bool(false)

Notice: Object of class Foo could not be converted to bool in /in/mreGe on line 15
bool(false)

Notice: Object of class Foo could not be converted to int in /in/mreGe on line 16
bool(false)

Notice: Object of class Foo could not be converted to float in /in/mreGe on line 17
bool(false)

I can't find any logic in current behavior:

• Why I can compare non-stringable object with string or bool, but can't compare with int/float?
• Why I can compare non-stringable object with string without notice?
• If object can't be converted to int/float why comparation return true?

PHP Version

PHP 8.0.22

Operating System

No response

Reproduce the comparison snippet on the reported PHP 8.0.22 version and inspect the PHP documentation covering object comparisons and type juggling. The work is done when the differing results and conversion notices are explained clearly in the relevant documentation, or the issue is narrowed to a PHP runtime bug.