append method

void append(
  1. String name,
  2. JSAny blobValueOrValue, [
  3. String filename
])

The append() method of the FormData interface appends a new value onto an existing key inside a FormData object, or adds the key if it does not already exist.

The difference between FormData.set and append() is that if the specified key already exists, set() will overwrite all existing values with the new one, whereas append() will append the new value onto the end of the existing set of values.

Implementation

external void append(
  String name,
  JSAny blobValueOrValue, [
  String filename,
]);