COP 2551_043key Chapter 2 Quiz Name ______________________KEY_____________ 6/3/2004 Given the following declarations, answer questions 1, 2, & 3. int x = 2; int y = 10; int z = 23; 1. What is the value of the Java expression x + y * z 232 2. What is the value of the Java expression z – y / x 18 3. What is the value of the Java expression x + z % y 5 4. Write a complete Java program that will store 88 in a variable named keys and will then use the variable and a println statement to output the message below (no comments or skipped lines are required, but use indentation as demonstrated in the text and in class). A piano has 88 keys. public class Keys { public static void main(String[] args) { keys = 88; System.out.println("A piano has " + keys + " keys."); } } 5. All floating point literals are of type a. b. c. d. 6. either either either any of true or false <==== 0 or 1 (zero or one) yes or no the above can be assigned to a Boolean variable You are less likely to lose information when you use a widening conversion. Which of the following is a widening conversion? a. b. 8. <==== Which of the following can be assigned to a Boolean variable? a. b. c. d. 7. float double int long Storing a short in an int. Storing a double in a float. <==== Given the following declaration: String name; For 5 points each, show two methods for creating the String object "John Doe" and assigning it to the reference variable called name. name = new String("John Doe"); name = "John Doe"; 9. DateFormat and DecimalFormat are both classes that are part of Java's text package (java.text). Write a single statement that will allow either of those classes to be referenced in your program without the need to always use the explicit package name. import java.text.*; 10. If the String variable major is initialized to "Computer Science", what is returned by major.charAt(4)? a. b. c. d. 'p' "Comp" 'u' "Compu" <==== 5 POINTS EXTRA CREDIT The Math class has a method named pow that is defined as: static double pow (double num, double power) Suppose you want to raise 3 to the 5th power and assign the result to a variable declared as double num; Write the Java statement that will do this: double num = java.Math.pow(3,5); or double num = Math.pow(3,5); // assuming there was an import statement // "double" is not needed if you assume "num" was already declared as a double. Any of the above will be accepted even if the assumptions were not stated.