1var object = {};
2formData.forEach(function(value, key){
3    object[key] = value;
4});
5var json = JSON.stringify(object);
6
7// Or ES6 arrow function
8var object = {};
9formData.forEach((value, key) => object[key] = value);
10var json = JSON.stringify(object);
11

1function buildFormData(formData, data, parentKey) {
2  if (data && typeof data === 'object' && !(data instanceof Date) && !(data instanceof File)) {
3    Object.keys(data).forEach(key => {
4      buildFormData(formData, data[key], parentKey ? `${parentKey}[${key}]` : key);
5    });
6  } else {
7    const value = data == null ? '' : data;
8
9    formData.append(parentKey, value);
10  }
11}
12
13function jsonToFormData(data) {
14  const formData = new FormData();
15  
16  buildFormData(formData, data);
17  
18  return formData;
19}
20
21const my_data = {
22  num: 1,
23  falseBool: false,
24  trueBool: true,
25  empty: '',
26  und: undefined,
27  nullable: null,
28  date: new Date(),
29  name: 'str',
30  another_object: {
31    name: 'my_name',
32    value: 'whatever'
33  },
34  array: [
35    {
36      key1: {
37        name: 'key1'
38      }
39    }
40  ]
41};
42
43jsonToFormData(my_data)
44

1var object = {};
2formData.forEach(function(value, key){
3    object[key] = value;
4});
5var json = JSON.stringify(object);
6

1`const formDataObject = (formData) => {
2
3for (const key in formData) {
4    if (formData[key].startsWith('{') || formData[key].startsWith('[')) {
5        try {
6            formData[key] = JSON.parse(formData[key]);
7            console.log("key is :", key, "form data is :", formData[key]);
8
9        } catch (error) {
10            console.log("error :", key);
11        }
12    }
13}
14
15console.log("object", formData)
16}`
17