访问JSON数组PHP中的值

I am not having any success getting values out of a JSON array object. I am specifically trying to get to geometry->location->lat

Here is what I am doing:

    $url='http://maps.googleapis.com/maps/api/geocode/json?address='.$a.'&sensor=false';
    $result = file_get_contents($url);
    $jsonArr = json_decode($result,true);

    echo "Lat: ".$jsonArr['results']['geometry']['location']['lat'];

Here is a print_r() of the JSON returned by Google:

 {
       "results" : [
          {
             "address_components" : [
                {
                   "long_name" : "46814",
                   "short_name" : "46814",
                   "types" : [ "postal_code" ]
                },
                {
                   "long_name" : "Fort Wayne",
                   "short_name" : "Fort Wayne",
                   "types" : [ "locality", "political" ]
                },
                {
                   "long_name" : "Indiana",
                   "short_name" : "IN",
                   "types" : [ "administrative_area_level_1", "political" ]
                },
                {
                   "long_name" : "United States",
                   "short_name" : "US",
                   "types" : [ "country", "political" ]
                }
             ],
             "formatted_address" : "Fort Wayne, IN 46814, USA",
             "geometry" : {
                "bounds" : {
                   "northeast" : {
                      "lat" : 41.08472709999999,
                      "lng" : -85.26534090
                   },
                   "southwest" : {
                      "lat" : 41.00163510,
                      "lng" : -85.35540899999999
                   }
                },
                "location" : {
                   "lat" : 41.05472940,
                   "lng" : -85.30328109999999
                },
                "location_type" : "APPROXIMATE",
                "viewport" : {
                   "northeast" : {
                      "lat" : 41.08472709999999,
                      "lng" : -85.26534090
                   },
                   "southwest" : {
                      "lat" : 41.00163510,
                      "lng" : -85.35540899999999
                   }
                }
             },
             "types" : [ "postal_code" ]
          }
       ],
       "status" : "OK"
    }

The results are returned in an array. Get the first element and you're done. However you should make sure that you actually have at least one element in the results array.

echo "Lat: " . $jsonArr['results'][0]['geometry']['location']['lat'];