send JavaScript array through jQuery AJAX POST

Question

What I want to do is send an JavaScript Array to a PHP file.
This is what I got:

var mydata = [];
 console.log(document.getElementsByTagName("input")[0].name);
 for (var i = 0; i < document.getElementsByTagName('input').length; i++) {
 mydata[document.getElementsByTagName("input")[i].name] = document.getElementsByTagName("input")[i].value;
 };
 for (var i = 0; i < document.getElementsByTagName('select').length; i++) {
 mydata[document.getElementsByTagName("select")[i].name] = document.getElementsByTagName("select")[i].value;
 };
 console.log(mydata);
 $.ajax({
 method: "POST",
 url: "q.php",
 data: {'lol': JSON.stringify(mydata)},
 contentType: 'application/json',
 dataType: 'json'
 })
 .done(function( msg ) {
 alert( "Data Saved: " + msg );
 $('#debug').html(msg);
 });

So as you can see, I create an array with a loop, at that moment all is fine. The problem is when I try to sent it through POST with JSON. I don't know if this is the best method...

I tried without JSON.stringify(); but the $_POST still empty

It seems like the post isn't sent, but I can see in the console the XHR post request has been sent.

• Justin Helgerson: You said: "but the same error occurs". What is the error? Can you provide the error message?
• ecarrizo: The POST that you see contains the data that you need? I think that the JSON.stringify is not necessary. you are getting a response error or a javascript error?
• wwwanaya: EDIT The $_POST is empty, I tried with out the JSON.stringify but it still empty.
• Bankzilla: Edit your question with what the mydata variable contains
• wwwanaya: Ok @Bankzilla. Give me a moment

Answer 1

Try to use this code and see the changes.

remove the contentType: 'application/json', dataType: 'json'

And change var mydata = [] into var mydata = {}

your ajax should look like this

 $.ajax({
 method: "POST",
 url: "q.php",
 data: {'lol': mydata}
 })
 .done(function( msg ) {
 alert( "Data Saved: " + msg );
 $('#debug').html(msg);
 });

You dont have to stringify your mydata because you already decleared it as object.

Hope it helps