使用PHP进行JSON解码

我正在做一些JSON解码-我按照本教程进行了很好的解释-如何使用PHP解析JSON

I am doing some JSON decodes - I followed this tutorial well explained - How To Parse JSON With PHP

和PHP代码，我使用了

and the PHP code, I used

 <?php
 $string='{"person":[
            {
                "name":{"first":"John","last":"Adams"},
                "age":"40"
            },
            {
                "name":{"first":"Thomas","last":"Jefferson"},
                "age":"35"
            }
         ]}';

$json_a=json_decode($string,true);

$json_o=json_decode($string);


// array method
foreach($json_a[person] as $p)
{
echo '

Name: '.$p[name][first].' '.$p[name][last].'

Age: '.$p[age].'

';

}




// object method
foreach($json_o->person as $p)
{
echo '

<br/> Name: '.$p->name->first.' '.$p->name->last.'

Age: '.$p->age.'

';
}


 ?>

工作正常...但我担心，我只需要Thomas姓氏和年龄的详细信息。我需要处理它以便仅提取某些功能，而不是所有对象。

It is working correctly... But my concern I need only details of Thomas' last name and age. I need to handle this to extract only certain features, not all the objects.