Re: in_array breaks down for 0 as value

On 22 Nov 2008, at 00:06, Ashley Sheridan wrote:

On Fri, 2008-11-21 at 09:11 +0000, Stut wrote:

On 20 Nov 2008, at 23:09, Ashley Sheridan wrote:

On Thu, 2008-11-20 at 09:25 +0000, Stut wrote:

On 20 Nov 2008, at 06:55, Yashesh Bhatia wrote:

I wanted to use in_array to verify the results of a form submission for a checkbox and found an interesting behaviour. $ php -v PHP 5.2.5 (cli) (built: Jan 12 2008 14:54:37) $ $ cat in_array2.php <?php $node_review_types = array(

                        'page'       => 'page',
                        'story'      => 'story',
                        'nodereview' => 'abc',
                        );

if (in_array('page', $node_review_types)) { print "page found in node_review_types\n"; } if (in_array('nodereview', $node_review_types)) { print "nodereview found in node_review_types\n"; } ?> $ php in_array2.php page found in node_review_types $ This works fine. but if i change the value of the key 'nodereview' to 0 it breaks down. $ diff in_array2.php in_array3.php 6c6

<                            'nodereview' => 'abc',

---

                        'nodereview' => 0,

$ $ php in_array3.php page found in node_review_types nodereview found in node_review_types $ Any reason why in_array is returning TRUE when one has a 0 value on the array ?

That's weird, 5.2.6 does the same thing. There's actually a comment about this on the in_array manual page from james dot ellis at gmail dot com... <quote> Be aware of oddities when dealing with 0 (zero) values in an array... This script: <?php $array = array('testing',0,'name'); var_dump($array); //this will return true var_dump(in_array('foo', $array)); //this will return false var_dump(in_array('foo', $array, TRUE)); ?> It seems in non strict mode, the 0 value in the array is evaluating to boolean FALSE and in_array returns TRUE. Use strict mode to work around this peculiarity. This only seems to occur when there is an integer 0 in the array. A string '0' will return FALSE for the first test above (at least in 5.2.6). </quote> So use strict mode and this problem will go away. Oh, and please read the manual before asking a question in future. -Stut --http://stut.net/

What about using the === and !== comparisons to compare and make sure that 0 is not giving a false false.

That's effectively what using strict mode does. RTFM please. -Stut

Hey, chill. If you offer advice, don't be so offensive to everyone.

I don't believe I was being offensive, you're clearly a very delicate little flower. The way I saw it you made a suggestion without understanding how to use the function in question. In my opinion RTFM is a perfectly reasonable response to that. -Stut -- http://stut.net/