获取未定义的偏移量：检索twitter URL实体时出错0

This is my code:

$latesttweets = $twitterconn>get("https://api.twitter.com/1.1/statuses/user_timeline.json?screen_name=".$twitter_id."&count=".$limit);


foreach ( $latesttweets as $tweet ){
   ...


   $text_url = $tweet->entities->urls[0]->url; // this line gives an error

   // test
   echo $text_url; // this line doesn't give an error



   ... code for display tweet ...
}

I'm trying to retrieve the url from the object:

"urls": [{
  "url": "https:\/\/t.co\/XdXRudPXH5",
  "expanded_url": "https:\/\/blog.twitter.com\/2013\/rich-photo-experience-now-in-embedded-tweets-3",
  "display_url": "blog.twitter.com\/2013\/rich-phot\u2026",
  "indices": [80, 103]
}],

as shown here.

The funny thing is, I've tried echoing and it works, except that the error Notice: Undefined offset: 0 and Notice: Trying to get property of non-object which follows on the next line keeps appearing.

(Note: The same goes for all the other arrays in the urls array. I'm kind of sure it's something to do with the ..->urls[0]->.., but I see no other way.)

Am I doing something wrong?

Ok the issue is urls[0]-> not a valid object in PHP and you should use

$text_url = $tweet->entities->urls{'0'}->url;

instead.

However in PHP 5+ the urls[0]-> should work

Here is the example.

$str = '{
    "text": "Four more years. http://t.co/bAJE6Vom",
    "entities": {
        "hashtags": [],
        "symbols": [],
        "urls": [
            {
                "url": "https://t.co/XdXRudPXH5",
                "expanded_url": "https://blog.twitter.com/2013/rich-photo-experience-now-in-embedded-tweets-3",
                "display_url": "blog.twitter.com/2013/rich-phot…",
                "indices": [
                    80,
                    103
                ]
            }
        ],
        "user_mentions": [],
        "media": [
            {
                "id": 266031293949698050,
                "id_str": "266031293949698048",
                "indices": [
                    17,
                    37
                ],
                "media_url": "http://pbs.twimg.com/media/A7EiDWcCYAAZT1D.jpg",
                "media_url_https": "https://pbs.twimg.com/media/A7EiDWcCYAAZT1D.jpg",
                "url": "http://t.co/bAJE6Vom",
                "display_url": "pic.twitter.com/bAJE6Vom",
                "expanded_url": "http://twitter.com/BarackObama/status/266031293945503744/photo/1",
                "type": "photo",
                "sizes": {
                    "medium": {
                        "w": 600,
                        "h": 399,
                        "resize": "fit"
                    },
                    "thumb": {
                        "w": 150,
                        "h": 150,
                        "resize": "crop"
                    },
                    "small": {
                        "w": 340,
                        "h": 226,
                        "resize": "fit"
                    },
                    "large": {
                        "w": 800,
                        "h": 532,
                        "resize": "fit"
                    }
                }
            }
        ]
    }
}

';

$tweet = json_decode($str);
$text_url = $tweet->entities->urls{0}->url;
echo $text_url ;