Why is foreach over a results object not working?

Question

I realize there are quite a few questions of this nature, but I have not been able to solve my issue using the other posts, so I was hoping someone here may be able to help me out.

I have an object I'm getting back from Yahoo local search API. I have passed the results into json_decode() and saved the results to $yahoo_json_decoded. I can get data from the results using a for loop and doing the following:

echo 'Name: ' . $yahoo_json_decoded->ResultSet->Result[$i]->Title . '<br />' ;

But I can't seem to be able to make the foreach work:

foreach($yahoo_json_decoded->ResultSet as $res=>$variable)
{
    $listingID = $yahoo_json_decoded->ResultSet[$res]->id ;
    echo $listingID;
}

I could just loop the data and move on, but I really want to understand why the foreach isn't working.

Thanks (show mercy)

Kirk

Answer 1

The literal difference between the two loops

The for loop in your snippet iterates over the array $yahoo_json_decoded->ResultSet->Result, while the foreach loop iterates over the object $yahoo_json_decoded->ResultSet.

In other words, in the for loop you're iterating over the array elements as you expect, whereas in the foreach loop you are in fact iterating over the object properties.

A demonstration of the difference

For example, given this object:

$json = json_encode(array('result'=>array('apple','orange','lemon')));
$obj  = json_decode($json);

consider the difference between this loop:

for ($i=0; $i < count($obj->result); $i++) :
    echo $i.' - '.$obj->result[$i].' ';
endfor;

and this loop:

foreach ($obj as $key=>$val) :
    echo $key.' - ';
    var_dump($val);
endforeach;

The output of the first loop will be:

0 - apple 1 - orange 2 - lemon

While the output of the second will be:

result - array(3) { [0]=> string(5) "apple" [1]=> string(6) "orange" [2]=> string(5) "lemon" }

See the difference in action

Answer 2

Based on $yahoo_json_decoded->ResultSet->Result[$i]->Title which you say works:

foreach($yahoo_json_decoded->ResultSet->Result as $index => $result)
{
   $listingID = $result->id ;
    echo $listingID;
}

Answer 3

From what I understand, you should be doing

foreach($yahoo_json_decoded->ResultSet->Result as $key => $val) //(...)

Answer 4

you're missing a layer of Data structure in your foreach loop

foreach($yahoo_json_decoded->ResultSet->Result as $res=>$variable)
{
   $listingID = $variable->id ;
    echo $listingID;
}

versus your for loop

for ($i = 0; $i <10; $i++)
$yahoo_json_decoded->ResultSet->Result[$i]->Title

thus

$i = $res
$variable = $yahoo_json_decoded->ResultSet->Result[$i]