window.FormData

FormData()

FormData provides a way to construct a set of key/value pairs, which can be used in fetch(), XMLHttpRequest.

append(name, value, fileName)

Appends a key value pair into FormData. If the value is either ArrayBuffer and TypedArray, its buffer as well as the object are copied. However, if the value is a File object value, the File object is cloned but its content is not cloned. Consequently, the File object and the cloned one refer to the same content.

See: FormData - append
Since: v7.3.0

Param	Type	Description
name	`string`	Key string for the pair
value	`string` \| `ArrayBuffer` \| `TypedArray` \| `File` \| `Blob`	Value for the pair
fileName	`string`	'Optional' file name to use for a File or a Blob object value. The default filename is "blob" for Blob object and the file name would be taken from the name property for File object.

delete(name)

Removes all entries from FormData whose name is same with the input name.

See: FormData - delete
Since: v7.3.0

Param	Type	Description
name	`string`	Name of the key to delete

entries()

Returns an iterator which iterates through all key/value pairs contained in the FormData. The key of each pair is a string object and the value is either a string or a Blob object.

Returns: iterator - Iterator for all key-value pairs in FormData.
See: FormData - entries
Since: v7.3.0

get(name)

Returns the first value associated with a given key from within a FormData object. Use getAll() if you expect multiple values and want all of them.

Returns: string | Blob - Value whose key matches the specified name. Otherwise, null.
See: FormData - get
Since: v7.3.0

Param	Type	Description
name	`string`	Name of the key to retrieve

getAll(name)

Returns all the values associated with a given key from within a FormData object.

Returns: Array - Array of values whose key matches the specified name. Otherwise, an empty list.
See: FormData - getAll
Since: v7.3.0

Param	Type	Description
name	`string`	Name of the key to retrieve

has(name)

Test if a FormData object contains a certain key.

Returns: boolean - True if a key of FormData matches the specified name. Otherwise, false.
See: FormData - has
Since: v7.3.0

Param	Type	Description
name	`string`	Name of the key to test

keys()

Returns an iterator which iterates through all keys in FormData. The keys are strings.

Returns: iterator - Iterator of FormData's keys.
See: FormData - keys
Since: v7.3.0

set(name, value, filename)

If there are entries whose name is same with the input name, replaces the first existing entry with new entry and removes the others. If not, appends a new entry with name/value.

See: FormData - set
Since: v7.3.0

Param	Type	Description
name	`string`	Name of the field
value	`string` \| `Blob`	Field's value. The value is converted to a string if the value is neither string nor Blob.
filename	`string`	Filename reported to the server when a Blob object or a File object is passed as a value. The default filename is "blob" for Blob object and the file name would be taken from the name property for File object.