PHP：如何在 Javascript 中将 json 解码回数组形式？

Question

I've an array in my php called as $tempoHeader , for example:

Example Array $tempoHeader

-------
Array
(
   [0] => red
   [1] => green
   [2] => yellow
   [3] => blue
)

I want to send it into my external javascript , so I do this one in my php code :

My PHP: header.php

$tempoHeader = array_diff_assoc($modelData, $data);
<script type="text/javascript">var header = <?php echo json_encode($tempoHeader); ?>;</script>
<script type="text/javascript" src="upload_header.js"></script>

In my javascript , I've try to console.log(header); and I got this in my console

Array [ "red", "green", "yellow", "blue" ]

My JS: upload_header.js

$(window).load(function() {
console.log(header);                    //this work and print out the header json
   var myObject = JSON.parse(header);
   var myArray = jQuery.parseJSON(header);
   console.log(myArray);                   //didn't print out anything
   console.log(myObject);                  //didn't print out anything
});

How do I can decode this json back as $tempoHeader array form?

Note : I've read this issue jQuery JSON Decode ( PHP to Javascript) , and I've try the suggestion such as jQuery.parseJSON(header); , JSON.parse(header); but I got nothing

Answer 1

$res = json_decode( $tempoHeader, true );
echo $res->array_name[index];

I hope this help

Answer 2

header already is an array, it is not json / a string and you do not need to parse it.

You send this to javascript:

var header = <?php echo json_encode($tempoHeader); ?>;    

So you already have an array in javascript as you have noticed:

Array [ "red", "green", "yellow", "blue" ]

And then you try to parse that as json:

var myObject = JSON.parse(header);

That is not possible nor is it necessary: json is a string and JSON.parse() expects a string as its parameter. You cannot use it on an array.

To use your variable, you can simply use header[0] (red), etc. or loop over it like you do with any other javascript array.

Answer 3

The Problem here is that when you executes your JavaScript, your PHP Script was already executed, to "send a variable back to php" you have to create a new Request.

Mostly it is done via Ajax OR you can add your Array in a hidden input field and "send" it with a form.

So you upload_header.js would look like

   $(function () {

        $.ajax('update_header.php', {
            method: 'POST',
            data: {
                'header': JSON.stringify(header)
            }
        })
    });

and in your "update_header.php" you would recieve the new header with

$newHeader = json_decode($_POST['header'],true);

hope this helps;)