Ajax post-POST数组在服务器端返回空

Question

I have an js function that is collecting data and sending it to a php file.

I am trying to submit an array as part of the post:

function send_registration_data(){

var string = "{username : " + $('#username').val() + ", password : " + $('#pass1').val() + ", level : " + $("#userrole").val() + ", 'property[]' : [";
var c = 0;
$('input[name=property]:checked').each(function(){
    if( c == 0){
        string +="\"" +this.value+"\"";
        c=1;
    } else {
        string +=",\""+this.value+"\"";
    }
});
string+="]}";
$('#input').html( JSON.stringify(eval("(" + string + ")")) );

$.ajax({ url: './php/submit_registration.php',
         //data: { username : $('#username').val() , password : $('#pass1').val() , email : $('#email').val() , level : $("#userrole").val() },
         data: JSON.stringify(eval("(" + string + ")")) ,
         type: 'post',
         success: function(output) {
                  $('#output').html( output );

            }
});
};

On submit my php file returns an the POST array as NULL. I am not sure what I am doing wrong here.

EDIT: IT is the same weather I try to convert the string to json or not.

ALso, the inputs contain just text names.

Answer 1

string keyword

Do not use the "string" keyword.

eval

Eval is evil - use it with caution.

strict mode

Make sure always to work in the "strict mode" by placing this line at the beginning of your code:

'use strict'

Building your response object

You do not have to glue your post object manually. Just do it this way:

var post = {
    'username': $('#username').val(),
    'password': $('#password').val(),
    'myArray[]': ['item1', 'item2', 'item3']
};

jQuery the right way

Avoid messing up with unnecessary syntax.

$.post(url, post)
    .done(function(response){
        // your callback
    });

Conclusion

'use strict'
var url = './php/submit_registration.php'; // try to use an absolute url
var properties = {};
$('input[name="property"]:checked').each(function() {
    properties.push(this.value);
});
var data = {
    'username':   $('#username').val(),
    'password':   $('#pass1').val(),
    'level':      $('#userrole').val(),
    'property[]': properties
};

// submitting this way
$.post(url, data)
    .done(function(response) {
        // continue
    })
    .fail(function(response) {
        // handle error
    });

// or this way
$.ajax({
    type: 'POST',
    url: url,
    data: JSON.stringify(data), // you'll have to change "property[]" to "property"
    contentType: "application/json",
    dataType: 'json',
    success: function(response) { 
        // continue
    }
});