FormData and fetch() by Google ¶

Integration with other places URLs are used ¶

By default, sending FormData in a fetch() API request creates a multipart body .

If you need it, URLSearchParams provides an alternative mechanism to POST data that’s urlencoded rather than mime multipart.

           const params = new URLSearchParams();
params.append('api_key', '1234567890');

fetch('https://example.com/api', {
  method: 'POST',
  body: params
}).then(...)

          

URLSearchParams also integrates with the URL constructor and a tags.

Both support our new buddy by providing a read-only property, .searchParams for accessing query params:

           const url = new URL(location);
const foo = url.searchParams.get('foo') || 'somedefault';

Links also get a .searchParams property:

           const a = document.createElement('a');
a.href = 'https://example.com?filter=api';

// a.searchParams.get('filter') === 'api';