json_encode（）; 在PHP功能

Question

I am trying to get expected json format after using json_encode($loc); in PHP.

$loc['location1'] =  Array(

                       "city"    =>"test",                  
                       "addr" => Array 
                                    (
                                        "addr1"=> "test",
                                        "addr2"=> "test"

                                    ),
                     );

expected json:

"location1": {
                "city": "test",
                "addr": {
                    "addr1": "test",
                    "addr2": "test"
                }
            }

instead of:

"0": {
            "location1": {
                "city": "test",
                "addr": {
                    "addr1": "test",
                    "addr2": "test"
                }
            }
        },

Please advise, thank you.

Answer 1

First as Leggendario said, your expected code is not valid json. To get a valid json it must be a value (quoted if it's not a number), an object or an array.

Second, to get something similar to your expectations based on your code you can do this:

$loc = array(
    "location1" => array(
        "city" => "test",                  
        "addr" => array(
            "addr1"=> "test",
            "addr2"=> "test"
        ),
    )
);

Then a call to:

json_encode($loc);

will output:

{
    "location1": {
        "city": "test",
        "addr": {
            "addr1": "test",
            "addr2": "test"
        }
    }
}

You can check your json outputs in http://jsonlint.com/

So basically what makes the difference is what you pass as a parameter to json_encode() .

Answer 2

There is a difference between an stdClass and an array. An stdClass in PHP is a generic empty class. In javascript this is defined as...

var obj = {};

An array is an index of values starting with the numeric index of 0. In javascript this is defines as...

var array = [];

In javascript you cannot have associative arrays in exact way you can define them in PHP. Therefore if you take your associative array in PHP and use json encode you will your associative key will have an index of 0.

$loc['location1'] in PHP becomes  0:[{'location'} etc...

The solution is to move this to an stdClass. The simplest way to do this is to replace array with stdClass and cast your array into an object with (object).

<?php
$loc  = new stdClass;

$loc->location = (object) Array(
                   "city"    =>"test",                  
                   "addr" => (object) Array 
                                (
                                    "addr1"=> "test",
                                    "addr2"=> "test"
                                ),
                 );
?>

This should do the trick.