The read-only size property of the Metadata interface specifies the size, in bytes, of the referenced file or other file system object on disk.

A number indicating the size of the file in bytes.

This example checks the size of a log file and removes it if it's larger than a megabyte.

workingDirectory.getFile(
  "log/important.log",
  {},
  (fileEntry) => {
    fileEntry.getMetadata((metadata) => {
      if (metadata.size > 1048576) {
        fileEntry.remove(() => {
          /* log file removed; do something clever here */
        });
      }
    });
  },
  handleError,
);

This feature has been removed from all specification and is not in the process of being standardized.

• File and Directory Entries API
• Introduction to the File and Directory Entries API
• Metadata
• FileSystemEntry.getMetadata()
• FileSystemFileEntry