如果你有多个相同名称的条目，例如如果你使用<SELECT multiple>或有多个<INPUT type="checkbox">具有相同的名称，你需要注意这一点，并将值创建一个数组。否则只能得到最后选中的值。

以下是es6的现代版本:

function formToJSON( elem ) {
  let output = {};
  new FormData( elem ).forEach(
    ( value, key ) => {
      // Check if property already exist
      if ( Object.prototype.hasOwnProperty.call( output, key ) ) {
        let current = output[ key ];
        if ( !Array.isArray( current ) ) {
          // If it's not an array, convert it to an array.
          current = output[ key ] = [ current ];
        }
        current.push( value ); // Add the new value to the array.
      } else {
        output[ key ] = value;
      }
    }
  );
  return JSON.stringify( output );
}

稍旧的代码(但IE11仍然不支持，因为它不支持ForEach或FormData上的条目)

function formToJSON( elem ) {
  var current, entries, item, key, output, value;
  output = {};
  entries = new FormData( elem ).entries();
  // Iterate over values, and assign to item.
  while ( item = entries.next().value )
    {
      // assign to variables to make the code more readable.
      key = item[0];
      value = item[1];
      // Check if key already exist
      if (Object.prototype.hasOwnProperty.call( output, key)) {
        current = output[ key ];
        if ( !Array.isArray( current ) ) {
          // If it's not an array, convert it to an array.
          current = output[ key ] = [ current ];
        }
        current.push( value ); // Add the new value to the array.
      } else {
        output[ key ] = value;
      }
    }
    return JSON.stringify( output );
  }

如果您正在使用lodash，可以使用fropairs简单地完成

import {fromPairs} from 'lodash';

const object = fromPairs(Array.from(formData.entries()));

这篇文章已经有一年了……但是，我真的非常非常喜欢ES6 @dzuc的答案。然而，它是不完整的，不能够处理多个选择或复选框。已经指出了这一点，并提供了代码解决方案。我发现它们很笨重，而且没有优化。所以我写了两个基于@dzuc的版本来处理这些情况:

对于ASP样式的表单，多个项目名称可以简单重复。

let r=Array.from(fd).reduce(
  (o , [k,v]) => (
     (!o[k])
     ? {...o , [k] : v}
     : {...o , [k] : [...o[k] , v]}
   )
   ,{}
);
let obj=JSON.stringify(r);

一行高手版:

Array.from(fd).reduce((o,[k,v])=>((!o[k])?{...o,[k]:v}:{...o,[k]:[...o[k],v]}),{});

对于PHP样式表单，其中多个项目名称必须有一个[]后缀。

let r=Array.from(fd).reduce(
  (o , [k,v]) => (
    (k.split('[').length>1)
    ? (k=k.split('[')[0]
      , (!o[k])
      ? {...o , [k] : [v]}
      : {...o , [k] : [...o[k] , v ]}
    )
    : {...o , [k] : v}
  )
  ,{}
);
let obj=JSON.stringify(r);

一行高手版:

Array.from(fd).reduce((o,[k,v])=>((k.split('[').length>1)?(k=k.split('[')[0],(!o[k])?{...o,[k]:[v]}:{...o,[k]:[...o[k],v]}):{...o,[k]:v}),{});

支持多级数组的PHP表单扩展。

Since last time I wrote the previous second case, at work it came a case that the PHP form has checkboxes on multi-levels. I wrote a new case to support previous case and this one. I created a snippet to better showcase this case, the result show on the console for this demo, modify this to your need. Tried to optimize it the best I could without compromising performance, however, it compromise some human readability. It takes advantage that arrays are objects and variables pointing to arrays are kept as reference. No hotshot for this one, be my guest.

let nosubmit = (e) => { e.preventDefault(); const f = Array.from(new FormData(e.target)); const obj = f.reduce((o, [k, v]) => { let a = v, b, i, m = k.split('['), n = m[0], l = m.length; if (l > 1) { a = b = o[n] || []; for (i = 1; i < l; i++) { m[i] = (m[i].split(']')[0] || b.length) * 1; b = b[m[i]] = ((i + 1) == l) ? v : b[m[i]] || []; } } return { ...o, [n]: a }; }, {}); console.log(obj); } document.querySelector('#theform').addEventListener('submit', nosubmit, {capture: true}); <h1>Multilevel Form</h1> <form action="#" method="POST" enctype="multipart/form-data" id="theform"> <input type="hidden" name="_id" value="93242" /> <input type="hidden" name="_fid" value="45c0ec96929bc0d39a904ab5c7af70ef" /> <label>Select: <select name="uselect"> <option value="A">A</option> <option value="B">B</option> <option value="C">C</option> </select> </label> <br /><br /> <label>Checkboxes one level:<br/> <input name="c1[]" type="checkbox" checked value="1"/>v1 <input name="c1[]" type="checkbox" checked value="2"/>v2 <input name="c1[]" type="checkbox" checked value="3"/>v3 </label> <br /><br /> <label>Checkboxes two levels:<br/> <input name="c2[0][]" type="checkbox" checked value="4"/>0 v4 <input name="c2[0][]" type="checkbox" checked value="5"/>0 v5 <input name="c2[0][]" type="checkbox" checked value="6"/>0 v6 <br/> <input name="c2[1][]" type="checkbox" checked value="7"/>1 v7 <input name="c2[1][]" type="checkbox" checked value="8"/>1 v8 <input name="c2[1][]" type="checkbox" checked value="9"/>1 v9 </label> <br /><br /> <label>Radios: <input type="radio" name="uradio" value="yes">YES <input type="radio" name="uradio" checked value="no">NO </label> <br /><br /> <input type="submit" value="Submit" /> </form>

我在这里迟到了。但是，我做了一个简单的方法来检查输入type="checkbox"

var formData = new FormData($form.get(0));
        var objectData = {};
        formData.forEach(function (value, key) {
            var updatedValue = value;
            if ($('input[name="' + key + '"]').attr("type") === "checkbox" && $('input[name="' + key + '"]').is(":checked")) {
                updatedValue = true; // we don't set false due to it is by default on HTML
            }
            objectData[key] = updatedValue;
        });
var jsonData = JSON.stringify(objectData);

我希望这能帮助到其他人。

为我工作

                var myForm = document.getElementById("form");
                var formData = new FormData(myForm),
                obj = {};
                for (var entry of formData.entries()){
                    obj[entry[0]] = entry[1];
                }
                console.log(obj);

的一行程序!

Array.from(fd).reduce((obj, [k, v]) => ({...obj, [k]: v}), {});

今天我了解到firefox有对象扩展支持和数组解构!