Undefined offset :0 ..., While that's defined

Question

I wrote a code like this in a function:

preg_match_all('/{ali\s+([^}\s]+)\s*}/', $row->text, $matches, PREG_SET_ORDER);
$m=$matches[0][1];

When I write this:

$row->text=$m;

It returns the value (for example "name" in "{ali name}" and "id" in "{ali id}"),but when I write this:

$a->name='hasan';
$a->id='14';
$row->text=$a->$m;

It says:

Notice: Undefined offset: 0 in ... on line 2

What's the problem?! I tested existance of spaces,tabs,etc in the string but there was not any of them!

Well do a `print_r($matches)` to see the structure of the array, and based on the result you construct further your code. Simple. — HamZa, Aug 05 '13 at 09:52
I did print_r($matches), that exist. I said it returns my string when I use $row->text=$m; — user1904238, Aug 05 '13 at 09:54
Should `$row->text=$a->$m;` not be `$row->text=$a->m;` or `$row->text=$a->name.' '.$a->id;` — MDEV, Aug 05 '13 at 09:54
@user1904238 ok, provide the **full** code you're using and tell us on which line you get the error. From what you have written, the error is on line 2 which means `$m=$matches[0][1];` is triggering the error. — HamZa, Aug 05 '13 at 09:58

score 2 · Accepted Answer · answered Aug 05 '13 at 09:51

2

Try with isset() checking

if(isset($matches[0][1])){
//Code here
}

answered Aug 05 '13 at 09:51

웃웃웃웃웃

Or better still, check the return value of `preg_match_all`. – cmbuckley Aug 05 '13 at 09:54
I know that exists! It returns my string when I use $row->text=$m; – user1904238 Aug 05 '13 at 09:55
Try print_r($matches) and check whther $matches[0] or $matches[0][1] exists or not after the preg_match() – 웃웃웃웃웃 Aug 05 '13 at 09:57
I,ve tried print_r($matches), yes, they exist! – user1904238 Aug 05 '13 at 10:00
2

It's just impossible that the index exists and you get an undefined offset error. Get real. – HamZa Aug 05 '13 at 10:13
The problem was that my function was operating in various places in the page but I wasn't know that! Thank you all – user1904238 Aug 05 '13 at 12:05

1 Answers1