The File.lastModifiedDateread-only property returns the last modified date of the file. Files without a known last modified date returns the current date .
In the File System API, a FileException object represents error conditions that you might encounter while accessing the file system using the synchronous API. It extends the FileException interface described in File Writer and adds several new error codes.
The FileReader interface's readAsArrayBuffer() method is used to start reading the contents of a specified Blob or File. When the read operation is finished, the readyState becomes DONE, and the loadend is triggered. At that time, the result attribute contains an ArrayBuffer representing the file's data.
The LocalFileSystem interface of the File System API gives you access to a sandboxed file system. The methods are implemented by window and worker objects.
The LocalFileSystemSync interface of the File System API gives you access to a sandboxed file system. It is intended to be used with WebWorkers. The methods are implemented by worker objects.
The FileSystemFileEntry interface of the File System API represents a file in a file system. It offers properties describing the file's attributes, as well as methods for creating a FileWriter object to write to the file or a File object to read the file.