Trouble looping through an array created from a foursquare JSON feed

问题

I'm working on a side project and at its core, I need to get a foursquare json feed into an array that i can loop through. My code is below and results in the following error:

Warning: Invalid argument supplied for foreach() in /homepages/7/d346835943/htdocs/dealrub/results.php on line 56

Here is an example of the json feed that i am correctly acquiring:

$jsonurl = "http://api.foursquare.com/v2/venues/search?ll=".$lat.",".$lon."&limit=100";
$json = file_get_contents($jsonurl,0,null,null);
$json_output = json_encode($json, true);

foreach ( $json_output->response->groups[0]->items as $items )
{
     echo "{$items->name}\n";
}

Any help as to what i'm doing wrong would be greatly appreciated. I left the jsonurl without my api key, but it is successfully returning the json results.

回答1:

You have to use json_decode.
Check whether $json_ouput is not empty.
You are passing true as second argument to json_decode (assuming you have it right) which means that it returns an associative array.

Either omit that:
```
$json_output = json_decode($json);
```
or access items as array:
```
foreach ( $json_output['response']['groups'][0]['items'] as $items )
```