On Wed, May 14, 2014 at 8:55 PM, Rain Lee <root@xxxxxxx> wrote: > So, here is the TLDR; > > $string = 'this is a string'; > > In PHP 5.5 > isset($string['check']) === false > isset($string['check'][0]) === true > > Why can't let > isset($string['check']) === false > isset($string['check'][0]) === false <-- > > ? > > On Thu, May 15, 2014 at 12:27 AM, Jim Lucas <lists@xxxxxxxxx> wrote: > > On 05/13/2014 08:22 AM, \R\N wrote: > >> > >> Greeting guys, > >> > >> I got a problem on checking and getting a string with multi dim index > >> (like > >> ['blablabla']['blabla']). It confusing me, so I think I need to found an > >> answer to clear myself. > >> > >> First of all, I known that is wrong to get something from a string > using a > >> multi dim index or even a string index. I did it by mistakenly set a > wrong > >> parameter. The parameter supposed to be array with string as index (That > >> will actually be a hashmap), but I setted a string on it. > >> > >> As result, I got a warning raised: Illegal string offset. > >> > >> It's normal since I use the string as index to attempt to getting > >> something > >> from a string. But the strange thing is, I did the isset check before > use > >> the index. It supposed to be hot pass the check, but it did. > >> > >> So I made a shorter test here: > >> > >> > https://gist.github.com/raincious/682ba152dbd74537e323#file-stringisset-php > >> > >> The test 1 is what I used in my application, it checks if the array > index > >> is > >> set and not empty in same time. A valid param for it should be like > this: > >> > >> $string = array( > >> 'check' => 'yes', > >> ); // Please ignore the variable name > >> > >> But when the $string truly turned to a string, it become the source of > my > >> question. > >> > >> Please notice that, on document: > >> http://www.php.net/manual/en/function.isset.php says, "Checking > >> non-numeric > >> offsets of strings now returns FALSE." since 5.4, and I using 5.5. > >> > >> So the test 3 (isset($string['check']) one) running as expected, it > >> returns > >> false. However, the test1 (isset($string['check'][0]) one) is > unfortunatly > >> not, It actually returnning true. > >> > >> > >> I'm not a experter of PHP and I even need other people's help to read > PHP > >> source code, but in the information from the document and the talking > with > >> other people gives me some guts to guess the $string['check'][0] > actually > >> will be converted into $string[(int)'check'][0] and then into > >> $string[0][0], > >> so the test 1 can be pass. Is that right? > >> > >> So, what I want to know is, why there has two kind of behaviour for > isset? > >> Maybe it's better to let the isset($string['check'][0]) and > >> isset($string['check']) both return false? > >> > > > > What you are describing, and what is in your test script on github is > > extremely confusing. I'm still not sure what you think you are trying to > > accomplish with your tests. > > > > Can you give us a real world example of what it is you are trying to do? > > > > > >> > >> And sorry for my english, please ask if you confused by me. > >> > >> Thank you, > >> R > > > > > > > > -- > > Jim Lucas > > > > http://www.cmsws.com/ > > http://www.cmsws.com/examples/ > > > > -- > PHP General Mailing List (http://www.php.net/) > To unsubscribe, visit: http://www.php.net/unsub.php > > I think you switched the two: isset($string['check']) === true isset($string['check'][0]) === false 'check' is automatically converted to an int by PHP (since the array is numeric) which gives you $string[0] which is set. However, if you try ding $string[0][0] ($string['check'][0]) it will give you false since it does not exist. PHP is pretty flexible when it comes to using ints as strings and vice verse, you just need to know you are using them correctly. Also use var_dump() when doing checks to give you a better idea what PHP is doing behind the scenes. Aziz
