Question

When your program does file l/O what should you always do? O Use relative file paths O Use absolute file paths Create a new file for outout O Close files so that others can use them

Answer 1

1.b.use absolute file paths

2.d.foreach(object obj in listObject){}

3.b.create an abstract class for them,then add all trees to the same list at construction time.Use a foreach loop to iterate through and call update age on each item.

4.b.Create a dictionary which contains the book name as the key and a stack of people waiting for the book.