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The
open()
and
openAsync()
methods
of a FileStream object each include a
fileMode
parameter,
which defines some properties for a file stream, including the following:
-
The ability to read from the file
-
The ability to write to the file
-
Whether data will always be appended past the end of the
file (when writing)
-
What to do when the file does not exist (and when its parent
directories do not exist)
The following are the various file modes (which you can specify
as the
fileMode
parameter of the
open()
and
openAsync()
methods):
|
File mode
|
Description
|
|
FileMode.READ
|
Specifies that the file is open for reading
only.
|
|
FileMode.WRITE
|
Specifies that the file is open for writing.
If the file does not exist, it is created when the FileStream object is
opened. If the file does exist, any existing data is deleted.
|
|
FileMode.APPEND
|
Specifies that the file is open for appending.
The file is created if it does not exist. If the file exists, existing data
is not overwritten, and all writing begins at the end of the file.
|
|
FileMode.UPDATE
|
Specifies that the file is open for reading
and writing. If the file does not exist, it is created. Specify
this mode for random read/write access to the file. You can read
from any position in the file. When writing to the file, only the
bytes written overwrite existing bytes (all other bytes remain unchanged).
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