I want to convert following String to NSMuableArray.
var components: String = "library/book/science"
For example, I want to perform the following objective c code in Swift
NSArray *componentsArray = [@"library/book/science" componentsSeparatedByString:@"/"];
NSMutableArray *componentsMutableArray = [[NSMutableArray alloc] initWithArray:componentsArray];
[componentsMutableArray addObject:@"astronomy"];