Why is my FormData object always empty?

Question

I'm trying to add some data to formData like this:

params = {'code': 'h1'}
const formData: FormData = new FormData();
formData.append('parameters', JSON.stringify(params));

When I try to get the data from the formData like this: formData['parameters'] it returns undefined and formData.entries.length is 0. I looked at some sites and saw that this is the way to do that. What am I doing wrong?

Thanks.

Answer 1

Your FormData object is actually not empty. The way you are trying to access the data after appending it, is wrong.

For me the following works:

const params = {'code': 'h1'}
const formData = new FormData();
formData.append('parameters', JSON.stringify(params));

for (const entry of formData.entries())
{
    document.write(entry);
}

Side notes:

• As formData.entries() returns an interator object, there is no length property.
• There is also no indexer [] defined. So you need to retrieve values using the get() method as shown by Daniel Beck in his answer.