PHP：不能使用[]进行阅读 - 但它不是[]而是[$ counter]

Question

in general I think I understand what the error message means. But in my case, it's a riddle I didn't succeed in solving...

    $keywords_all = array();
    $count = 0;

    for ($z = 0; $z < $num_results; $z++)
    {
        $keywords_array = explode(",", $row['free_keywords']);

        for ($i = 0; $i < count($keywords_array); $i++)
        {
            if (in_array(strtolower(trim($keywords_array[$i])), $keywords_all))
            {
                $count++;
            }
            else
            {
                echo "<br />".$keywords_array[$i];
                $keywords_all[$count] = $keywords_array[$i];
            }
        }

        $row = pg_fetch_array($result);
    }

So, what's wrong with that one? The error message pops up in the line

    $keywords_all[$count] = $keywords_array[$i];

I have no clue, seems to be alright to me. But guess, it's again a tiny, tiny thing I've neglected... Thanks for any hints!

Answer 1

I was not able to reproduce your error message. I did find a bug in your code though (I am assuming that you are putting all your keywords in the $keywords_all array without any duplicates). So you should not increment $count inside your IF but instead update the $keywords_all count. See below:

if (in_array(strtolower(trim($keywords_array[$i])), $keywords_all)) {
    $count = count($keywords_all);
} else {
    echo "<br />".$keywords_array[$i];
    $keywords_all[$count] = $keywords_array[$i];
    $count++;
}

You will increment $count after storing a value to your $keywords_all array.