PHP通过删除空键来简化json数组

Question

I need to get data from an array, but the output always varies so sometimes it has more empty keys etc.

    $id = "1";
    $url = file_get_contents("http://example.com/?api={$id}");
    $json = json_decode($url, true);

    foreach($json as $data)
    {
        echo $data[0][0]["test"];
    }

The problem is that to print values from it have to always put the number of empty keys first like echo $data[0][0]["test"];

How can I make it possible to only write echo $data["test"]; under any circumstance no matter how many empty keys there are?

EDIT: The json array

[
    [
        {
            "test: "testing"
        }
    ]
]

Answer 1

 function printValue($array)
    foreach($array as $value){
     if(is_array($value)){
       printValue($value) 
     }
     else 
       echo $value;
  }
}

Basically a recursive function, if the value is an array dig down it else print the value.

This will work for all depths, be it on 2nd level or on 4th level.