FormData.set()

The set() method of the FormData interface sets a new value for an existing key inside a FormData object, or adds the key/value if it does not already exist.

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

Syntax

set(name, value)
set(name, value, filename)

Parameters

• name
  • : The name of the field whose data is contained in value.
• value
  • : The value of the field. This can be a string or a Blob (including subclasses such as File). If none of these, the value is converted to a string.
• filename optional
  • : The filename reported to the server when a Blob or File is passed as the second parameter. The default filename for Blob objects is "blob". The default filename for File objects is the file's filename.

Return value

undefined