$result = 1 && 0; in php4.3

[searain]

In the old php;

$result = 1 && 0;

$result will be 0.

But in the new php 4.3, the result is empty string?

is that the case?

thanks.

[searain]

or i was wrong.

$result = 1 && 0;
echo($result);

will return always nothing, both in old php and new php? i maybe just didn't catch that error before and i happend to catch that error after i updated the php so i may think it is the new version php thing.

thanks.

[searain]

<?php
$result = 1 && 1;
echo (" 1 && 1 ".$result);
echo("<br>");

$result = 1 && 0;
echo ("1 && 0  ".$result);
echo("<br>");

$result = 0 && 1;
echo ("0 && 1  ".$result);
echo("<br>");

$result =  0 && 0;
echo ("0 && 0  ".$result);
echo("<br>");

$result = 1 & 1;
echo (" 1 & 1  ".$result);
echo("<br>");

$result = 1 & 0;
echo ("1 & 0  ".$result);
echo("<br>");

$result = 0 & 1;
echo ("0 & 1  ".$result);
echo("<br>");

$result =  0 & 0;
echo ("0 & 0  ".$result);
echo("<br>");

?>

could anyone run this on php4.0 for me to see if it the same as php4.3? the follow is the result from php4.3.

1 && 1 1
1 && 0
0 && 1
0 && 0
1 & 1 1
1 & 0 0
0 & 1 0
0 & 0 0

Or the whole thing is php.ini set up issue?

thanks!

[diego25]

Since I've joined the PHP community (about 2.5 years ago), false was always empty string (actually, null value). But regardless of the value, you cannot do this:

if (1 && 0 == "")

'case you'd be comparing a boolean result with a string. You should take advantage of PHP's builtin constants true and false, e.g.

if (1 && 0 == false)

This way, if in PHP 99 the developers decide to change the return value of 1&&0 (i.e. false) to "incorrect", your code wouldn't be affected because the constant false would be changed accordingly.

Diego

[searain]

thanks!

so it is not old php and new php thing. it is my programming error.

i should use "bitwise and, & " there instead of "logical and, &&".