php - How do I fix this illegal offset type error

Question

I'm getting "illegal offset type" error for every iteration of this code. Here's the code in case anyone can help:

$s = array();

for($i=0;$i<20;$i++){

    $source = $xml->entry[$i]->source;
    $s[$source] += 1;

}

print_r($s)

Any ideas. Thanks in advance.

Answer 1

There are probably less than 20 entries in your xml.

change the code to this

for ($i=0;$i< sizeof($xml->entry); $i++)
...

Answer 2

var_dump($source);

Answer 3

Illegal offset type errors occur when you attempt to access an array index using an object or an array as the index key.

Example:

$x = new stdClass();
$arr = array();
echo $arr[$x];
//illegal offset type

Your $xml array contains an object or array at $xml->entry[$i]->source for some value of $i, and when you try to use that as an index key for $s, you get that warning. You'll have to make sure $xml contains what you want it to and that you're accessing it correctly.

Answer 4

check $xml->entry[$i] exists and is an object before trying to get a property of it

 if(isset($xml->entry[$i]) && is_object($xml->entry[$i])){
   $source = $xml->entry[$i]->source;          
   $s[$source] += 1;
 }

or $source might not be a legal array offset but an array, object, resource or possibly null