jQuery.submit() - json.parse(String) - json.stringify(Object)

JSON.parse is the opposite of JSON.stringify

JSON.parse(String)

var str = '{"hello":"world"}';
var obj = JSON.parse(str);
console.log(obj.hello);  // world

JSON.stringify(Object)

var obj = ...;
var json = JSON.stringify(obj);  
var obj2 = JSON.parse(json);



Jquery Submit
1. //prepare a handle first
$('#formID').submit(function(event) {

    //JQuery - getting submit data form
    var values = {};
    $.each($('#formID').serializeArray(), function(i, field) {
   values[field.name] = field.value;
   console.log(field.name+"\t"+values[field.name]);
    });


}

2. //subimit form
$('#formID').submit();


JQuery Validate Field Value

.val() will give you an input element's value.
if ($("#element").val() == "") alert ("Empty!");