json stringify file object return 7b 7d

1// get File Object  
2var fileObject = getFile();
3
4// reCreate new Object and set File Data into it
5var newObject  = {
6   'lastModified'     : fileObject.lastModified,
7   'lastModifiedDate' : fileObject.lastModifiedDate,
8   'name'             : fileObject.name,
9   'size'             : fileObject.size,
10   'type'             : fileObject.type
11};  
12
13// then use JSON.stringify on new object
14JSON.stringify(newObject);