Re: [PHP] Boolean Assignment Operator

[Thodoris]

2009/2/2 Gavin Hodge <gavin.ho...@gmail.com>
  
Hi,

I'm fairly new to PHP, having migrated from the Java / C# world.

I wrote some code similar to the following:

$success = true;
$success &= operation1();
$success &= operation2();

if ($success === true) {
   operation3(); // depends on 1 and 2 being successful
}

This didn't work as expected. After a bit of digging I found:
* The &= operation isn't mentioned anywhere in the PHP documentation
* The &= function seems to work as expected, however the following is
observed...
      $success = true;
      $success &= true;
      print $success == true; // outputs 1
      print $sucesss === true; // no output
* The 'or' assignment operator |= causes no errors but doesn't work.

Can any PHP gurus explain why the &= operator works at all, and why
=== seems to fail afterwards?

Cheers,
Gavin.
    


Hey,

never heard of the "|=" operator. So I think php does not support it.
  

Not true. This works just fine:

<?php
$a = 0;
$b = 1;

$a |= $b;
echo $a;
?>

And gives 1 as expected.

I cannot say how "&=" works in Java or C# but as of php it works like that
(IMO) (reference instead of copy):
$var1 = "test1";
$var2 = $var1;
$var3 &= $var1;
$var1 = "test2";

echo var1; // "test2"
echo var2; // "test1"
echo var3; // "test2"

  

The manual does describe these as "combined operators" in the assignment 
operators section. See the last example:

http://www.php.net/manual/en/language.operators.assignment.php



--
Thodoris