You can use
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSSharedPublicDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *filePath = [documentsDirectory stringByAppendingPathComponent:@"Playlist"];
if you want path of Documents directory replace first line by this
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);