如何使用php将多维数组转换为正确的JSON？

Question

I have an array that contains multiple entries of books. I store each books element with its unique id as its key in each. I'm struggling on generating correct JSON from this.

When i json_encode on the array it just generates each sub arrays json not grouping the elements by key but by which array they're in.

this is my multidimensional array

$booksarray = array("book title" => array(), "book isbn" => array(), "book borrowedcount" => array());

Im completely lost how to get elements out of each sub array and then group them together so that they output something like,

{"results": 
 {"course": "CC120", "books": 
   { "book": 
     [{"id": "12345", "title": "javascript", "isbn": "123456789", "borrowedcount": "45"}] } }

I have the XML outputing as follows

<results>
 <course>cc120</course>
  <books>
   <book id="9876" title="html" isbn="000001234" borrowedcount="56">
   <book id="12345" title="javascript" isbn="123456789" borrowedcount="45">
   <book id="222" title="php5" isbn="55555555" borrowedcount="22">
   <book id="23788" title="XML" isbn="99988877" borrowedcount="5">
  </books>
</results>

Any help will be greatly appreciated

Answer 1

Convert the array into the desired format, then json_encode() it:

$newArray = array();

foreach($booksarray["book title"] as $key => $title)
{
    $newArray[] = array(
        'id' => $key,
        'title' => $title,
        'isbn' => $booksarray["book isbn"][$key],
        'borrowedcount' => $booksarray["book borrowedcount"][$key]
    );
}

echo json_encode($newArray);

Answer 2

It looks like your array isn't in the format you'd like it to be in first. Once your php array is in the same structure that you want the json to be in, json_encode will work.

eg

$resultsArray = array(
    "results" => array(
        "course" => "CC120", 
        "books" => array(
            "book" => array(
                "id" => "12345", 
                "title" => "javascript"
                )
            )
        )
    );

$strJson = json_encode($resultsArray);

Answer 3

I think the problem might be in the way that you have structured your array. Are you able to change it?

I would suggest an array structure as follows:

$booksarray = array(
    "9876" => array(
         "title" => "html",
         "isbn" => "000001234", 
         "borrowedcount" => "56"
    ),
    "12345" => array(
         "title" => "javascript",
         "isbn" => "123456789", 
         "borrowedcount" => "45"
    )
);

json_encode() should then output this in the format you want.

Eg

{"9876":{"title":"html","isbn":"000001234","borrowedcount":"56"},"12345":{"title":"javascript","isbn":"123456789","borrowedcount":"45"}}