Re: A little confusing thing on (mistakenly) geting a offset from string with multi dim index.

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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/
>

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