const formData = new FormData(form);

let formDataJSON = {};

for (const [key, value] of formData.entries()) {

    formDataJSON[key] = value;
}

此函数返回转换为正确类型的所有值；

bool/string/（integer/floats）可能

虽然您需要jQuery来实现这一点，但由于serializeArray也是jQuery，所以没什么大不了的。

/**
 * serialized a form to a json object
 *
 * @usage: $("#myform").jsonSerialize();
 *
 */

(function($) {
    "use strict";
    $.fn.jsonSerialize = function() {
        var json = {};
        var array = $(this).serializeArray();
        $.each(array, function(key, obj) {
            var value = (obj.value == "") ? false : obj.value;
            if(value) {
                // check if we have a number
                var isNum = /^\d+$/.test(value);
                if(isNum) value = parseFloat(value);
                // check if we have a boolean
                var isBool = /^(false|true)+$/.test(value);
                if(isBool) value = (value!=="false");
            }
            json[obj.name] = value;
        });
        return json;
    }
})(jQuery);

这和你想要的完全一样

仅执行以下代码一次

$.fn.serializeObject = function(){
    let d={};
    $(this).serializeArray().forEach(r=>d[r.name]=r.value);
    return d;
}

现在您可以多次执行以下行

let formObj = $('#myForm').serializeObject();
// will return like {id:"1", username:"abc"}

此函数应处理多维数组以及多个同名元素。

到目前为止，我已经使用了几年：

jQuery.fn.serializeJSON=function() {
  var json = {};
  jQuery.map(jQuery(this).serializeArray(), function(n, i) {
    var _ = n.name.indexOf('[');
    if (_ > -1) {
      var o = json;
      _name = n.name.replace(/\]/gi, '').split('[');
      for (var i=0, len=_name.length; i<len; i++) {
        if (i == len-1) {
          if (o[_name[i]]) {
            if (typeof o[_name[i]] == 'string') {
              o[_name[i]] = [o[_name[i]]];
            }
            o[_name[i]].push(n.value);
          }
          else o[_name[i]] = n.value || '';
        }
        else o = o[_name[i]] = o[_name[i]] || {};
      }
    }
    else {
      if (json[n.name] !== undefined) {
        if (!json[n.name].push) {
          json[n.name] = [json[n.name]];
        }
        json[n.name].push(n.value || '');
      }
      else json[n.name] = n.value || '';      
    }
  });
  return json;
};

const formData = new FormData(form);

let formDataJSON = {};

for (const [key, value] of formData.entries()) {

    formDataJSON[key] = value;
}

这里有一种非jQuery方法：

    var getFormData = function(form) {
        //Ignore the submit button
        var elements = Array.prototype.filter.call(form.elements, function(element) {
            var type = element.getAttribute('type');
            return !type || type.toLowerCase() !== 'submit';
        });

您可以这样使用：

function() {

    var getFormData = function(form) {
        //Ignore the submit button
        var elements = Array.prototype.filter.call(form.elements, function(element) {
            var type = element.getAttribute('type');
            return !type || type.toLowerCase() !== 'submit';
        });

        //Make an object out of the form data: {name: value}
        var data = elements.reduce(function(data, element) {
            data[element.name] = element.value;
            return data;
        }, {});

        return data;
    };

    var post = function(action, data, callback) {
        var request = new XMLHttpRequest();
        request.onload = callback;
        request.open('post', action);
        request.setRequestHeader("Content-Type", "application/json;charset=UTF-8");
        request.send(JSON.stringify(data), true);
        request.send();
    };

    var submit = function(e) {
        e.preventDefault();
        var form = e.target;
        var action = form.action;
        var data = getFormData(form);
        //change the third argument in order to do something
        //more intersting with the response than just print it
        post(action, data, console.log.bind(console));
    }

    //change formName below
    document.formName.onsubmit = submit;

})();