JSON Post and Decode array to PHP - php

Question

I'm tring to post an array to PHP file using JSON. It does not work. The problem is nothing happens. If I decomment datatype:"json" then I get the alert (but without data).
This is my jquery code
var arr = new Array();
arr.push('1','Brussels|25');
arr.push('2','Antwerp|40');
$.ajax({
type: "POST",
contentType: "application/json; charset=utf-8",
url: "jsondecode.php",
data: JSON.stringify(arr),
dataType: "json",
success: function(data){alert(data);},
failure: function(errMsg) {
alert(errMsg);
}
});
And this is my PHP code (jsondecode.php);
<?php
$array = json_decode($_POST["arr"]);
foreach($array as $el){
$el_array=explode('|',$el);
echo"City=".$el_array[0]." And Age = ".$el_array[1]."";
}
?>
Does somebody know a useful tutorial on this?

Answer 1

You have to post the data in this format to retrieve like $_POST["arr"]
data: { arr : JSON.stringify(arr) },

Answer 2

What the heck are you trying?
It looks as if you are trying to put key-value-pairs to the JavaScript-Array with arr.push('1', 'Brussels|25'); expecting an array containing "Brussels|25" under the key "1" - but watch out, you are creating this array: ["1", "Brussels|25", "2", "Antwerp|40"].
If you want to send json, send json-data:
var arr= [{
"city" : "Brussels",
"age" : 25
},{
"city" : "Antwerp",
"age" : 40
}];
then your ajax call:
$.ajax({
type: "POST",
url: "jsondecode.php",
data: {arr: JSON.stringify(arr)},
success: function(data){
console.log("success:",data);},
failure: function(errMsg) {
console.error("error:",errMsg);
}
});
So you don't need to explode the data server-sided.
The server-sided script:
<?php
$data = json_decode($_POST["arr"]);
// will echo the JSON.stringified - string:
echo $_POST["arr"];
// will echo the json_decode'd object
var_dump($data);
//traversing the whole object and accessing properties:
foreach($data as $cityObject){
echo "City: " . $cityObject->city . ", Age: " . $cityObject->age . "<br/>";
}
?>
Hope, this helps you now.
#edit: By the way, use console.log() or console.error() instead of alert. Alert will cause scripts to pause until you click on ok and you cannot see objects in an alert.
#2nd edit: the script is now tested, I removed unnecessary code and added the server-sided code

Answer 3

Replace :
$array = json_decode($_POST["arr"]);
By:
$array = json_decode($_POST["arr"], true);

Answer 4

Worked for me:
JS:
$.ajax({
type: "POST",
contentType: "application/json; charset=utf-8",
url: "jsondecode.php",
data: JSON.stringify({"1": "Brussels", "2": "Antwerp"}),
success: function(data){alert(data);},
failure: function(errMsg) {
alert(errMsg);
}
});
PHP:
<?php
$p = file_get_contents('php://input');
$x = json_decode($p, true);
echo $x["1"];
?>