如何从嵌套的JSON数据获取值？

Question

Here's my JSON code:

{
    "query": {
        "count": 2,
        "created": "2013-04-03T09:47:03Z",
        "lang": "en-US",
        "results": {
            "yctCategories": {
                "yctCategory": {
                    "score": "0.504762",
                    "content": "Computing"
                }
            },
            "entities": {
                "entity": [
                    {
                        "score": "0.902",
                        "text": {
                            "end": "19",
                            "endchar": "19",
                            "start": "0",
                            "startchar": "0",
                            "content": "Computer programming"
                        },
                        "wiki_url": "http://en.wikipedia.com/wiki/Computer_programming"
                    },
                    {
                        "score": "0.575",
                        "text": {
                            "end": "51",
                            "endchar": "51",
                            "start": "41",
                            "startchar": "41",
                            "content": "programming"
                        }
                    }
                ]
            }
        }
    }
}

and below is my PHP code

$json_o = json_decode($json,true);
echo "Json result:</br>";
echo $json; // json
echo "</br></br>";
echo "Value result:</br>";
$result = array();
//$entity = $json_o['query']['results']['entities']['entity'];
foreach ($json_o['query']['results']['entities']['entity'] as $theentity)
 foreach ($theentity['text'] as $thetext){
    $result[] = $thetext['content'];
 }
print_r($result);

My expectation is to get the value of content in entity, which is " Computer programming " and " programming ".

I already searching around, but still have found the solution yet.

The result of my PHP code is:

Array ( [0] => 1 [1] => 1 [2] => 0 [3] => 0 [4] => C [5] => 5 [6] => 5 [7] => 4 [8] => 4 [9] => p ) 

Answer 1

Use this loop

foreach ($json_o['query']['results']['entities']['entity'] as $theentity)
{
    $result[] = $theentity['text']['content'];
}

http://codepad.viper-7.com/tFxh1w

Output Array ( [0] => Computer programming [1] => programming )

Answer 2

remove the second foreach and replace it with $result[] = $theentity['text']['content'];

using something like http://jsonlint.com/ might make it easier for you to see how the json is structured. alternatively just var_dump (or print_r ) the output of your json_decode .

Answer 3

Use simple code:

$array = $json_o['query']['results']['entities']['entity'];

foreach($array as $v){
  echo $v['text']['content'];
}

Answer 4

Change your foreach to:

$result = array();
foreach ($json_o['query']['results']['entities']['entity'] as $theentity) {
    $result[] = $theentity['text']['content'];
}
print_r($result);

$theentity['text'] is an array of keys => value. You can just access key content instead of looping through all of the entries.

Another way you could do it (though it is a poor choice) is:

foreach($theentity['text'] as $key => $value) {
    if( 'content' === $key ) {
        $result[] = $value;
    }
}

I provide this second example to demonstrate why the original code did not work.

Update

To access other properties like the yctCategories just do something similar

$categories = array();
foreach ($json_o['query']['results']['yctCategories'] as $yctCategory) {
    $categories[] = $yctCategory['content'];
}
print_r($categories);