json_decode after JSON stringify not working properly

Question

I have an javascript array which is json encoded and posted to PHP. when I check a value in the array before posting ie console.log(selection[878][2824]) I'm getting a value as its result. and then the variable is json encoded using JSON.stringify and posted to server. But when I json_decode the value in php and printed the same, I'm getting null array

js script

    console.log(selection);
    $http({
                method: 'POST',
                url: 'example.php',
                data: 'selection='+JSON.stringify(selection),
                headers: {'Content-Type': 'application/x-www-form-urlencoded'}
            })

php script

$selectionData = json_decode($_POST['selection']);
print_r($selectionData[878][2824]);

So what is happening while encoding the data here. How is it lost ?

Answer 1

似乎数据格式不正确，我认为您必须格式化字符串

"selection :"  +JSON.stringify(selection);

Answer 2

try this

js

$http({
            method: 'POST',
            url: 'example.php',
            data: {selection : JSON.stringify(selection)}
        })

php

$data = json_decode(file_get_contents("php://input"),true);
$selection = json_decode($data['selection'],true);

Answer 3

You do not have to stringify your content when you are using POST, just set the right headers.

$http({
            method: 'POST',
            url: 'example.php',
            data: selection,
            headers: {'Content-Type': 'application/json'}
        })

or if you need it with an identifier:

$http({
            method: 'POST',
            url: 'example.php',
            data: {"selection": selection },
            headers: {'Content-Type': 'application/json'}
        })

and in PHP (if you are using the additional identifier):

$selectionData = $_POST['selection'];