CMSC 131 Quiz 7 Worksheet
The next quiz will be on Monday, Nov 8 during your lab session (either at 10 am or 11
am). The following list provides more information about the quiz:
.
• It will be a written quiz (not using any computer).
• It will be closed-book, closed-notes, and no calculator is allowed.
• Answers must be neat and legible. We recommend that you use pencil and eraser.
• The quiz will be based on the exercises you will find below.
The following exercises cover the material to be covered in Quiz #7. Solutions to these
exercises will not be provided, but you are welcome to discuss your solutions with TAs
and instructors during office hours.
When asked for a “piece of code” you do not need to provide an entire class definition or
even an entire method. Just present the Java statements and any variable declarations as
needed to make your solution clear.
Problem 1
Write a method that implements the functionality of Double.parseDouble. That is, a
method that transforms a string into a double. Examples include “14.234”, “-13”,
“+.234”, and “0.0100”.
Problem 2
A Stack is a data structure frequently used in Computer Science. In this structure
elements are inserted and removed from the same end (similar to a stack of clean plates in
a dinner). Implement a class called MyStack which represents a Stack of String objects.
The specifications associated with the class are:
Instance variable
String[] array; // Array used to represent the stack.
// Feel free to add any other variables you may need.
Methods
• Constructor – Creates a stack with no elements. Hint: create an array with size 0.
• push – Adds an element to the top of the stack. It takes as parameter a reference to
a string. The method will create a duplicate of the string and will add the copy to
the stack. The array must be resized to accommodate the new element.
