BioMed Tech Exam Review

1. BioMed Tech Exam Review Chapter 4

2. The behavior of an object is defined by the object’s • instance data • constructor • visibility modifiers • methods • all of the above

3. The relationship between a class and an object is best described as • classes are instances of objects • objects are instances of classes • objects and classes are the same thing • classes are programs while objects are variables • objects are the instance data of classes

4. To define a class that will represent a car, which of the following definitions is most appropriate? • private class car • public class car • public class Car • public class CAR • private class Car

5. Which of the following reserved words in Java is used to create an instance of a class? • class • public • public or private, either could be used • import • new

6. In order to preserve encapsulation of an object, we would do all of the following except for which one? • Make the instance data private • Define the methods in the class to access and manipulate the instance data • Make the methods of the class public • Make the class final • All of the above preserve encapsulation

7. If a method does not have a return statement, then • it will produce a syntax error when compiled • it must be a void method • it can not be called from outside the class that defined the method • it must be defined to be a public method • it must be an int, double, or String method

8. Consider a sequence of method invocations as follows: main calls m1, m1 calls m2, m2 calls m3 and then m2 calls m4, m3 calls m5. If m4 has just terminated, what method will resume execution? • m1 • m2 • m3 • m5 • main

9. A variable whose scope is restricted to the method where it was declared is known as a(n) • parameter • global variable • local variable • public instance data • private instance data

10. A class’ constructor usually defines • how an object is initialized • how an object is interfaced • the number of instance data in the class • the number of methods in the class • if the instance data are accessible outside of the object directly

11. Having multiple class methods of the same name where each method has a different number of or type of parameters is known as • encapsulation • information hiding • tokenizing • importing • method overloading

12. Instance data for a Java class • are limited to primitive types (e.g., int, double, char) • are limited to Strings • are limited to objects(e.g., Strings, classes defined by other programmers) • may be primitive types or objects, but objects must be defined to be private • may be primitive types or objects

13. An example of passing a message to a String where the message has a String parameter occurs in which of the following messages? • length • substring • equals • toUpperCase • none of the above, it is not possible to pass a String as a parameter in a message to a String

14. Consider a method defined with the header: public void foo(int a, int b). Which of the following method calls is legal? • foo(0, 0.1); • foo(0 / 1, 2 * 3); • foo(0); • foo( ); • foo(1 + 2, 3 * 0.1);

15. Consider a method defined with the header: public void doublefoo(double x). Which of the following method calls is legal? • doublefoo(0); • doublefoo(0.555); • doublefoo(0.1 + 0.2); • doublefoo(0.1, 0.2); • all of the above are legal except for d

16. What is a mutator method? • A method that modifies a value. • A method that provides read-only access to a value. • A method that has the same name, but different parameters, as another method. • A method that is called when an object is first created. • A method that does not return a value.

17. BioMed Tech Exam Review Chapter 5

18. For the first four questions, assume x and y are String variables with x = "Hello" and y = null.

19. The result of (x = = y) is • true • false • a syntax error • a run-time error • x being set to the value null

20. The result of x.length( ) + y.length( ) is • 0 • 5 • 6 • 10 • a thrown exception

21. If the operation y = "Hello"; is performed, then the result of (x = = y) is • true • false • x and y becoming aliases • x being set to the value null • a run-time error

22. If the operation y = x; is performed, then the result of (x = = y) is • true • false • x being set to the value null while y retains the value "Hello" • y being set to the value null while x retains the value "Hello" • x being set to y, which it is already since y = x; was already performed

23. Consider the following swap method. If String x = "Hello" and String y = "Goodbye", then swap(x, y); results in which of the following? public void swap(String a, String b) { String temp; temp = a; a = b; b = temp; } • x is now "Goodbye" and y is now "Hello" • x is now "Goodbye" and y is still "Goodbye", but (x != y) • x is still "Hello" and y is now "Hello", but (x != y) • x and y are now aliases • x and y remain unchanged

24. Which of the following methods is a static method? The class in which the method is defined is given in parentheses following the method name. • equals (String) • toUpperCase (String) • sqrt (Math) • format (DecimalFormat) • paint (Applet)

25. Static methods cannot • reference instance data • reference non-static instance data • reference other objects • invoke other static methods • invoke non-static methods

26. An object that refers to part of itself within its own methods can use which of the following reserved words to denote this relationship? • inner • i • private • this • static

27. Which of the following interfaces would be used to implement a class that represents a group (or collection) of objects? • Iterator • Speaker • Comparable • MouseListener • KeyListener

28. In order to implement Comparable in a class, what method(s) must be defined in that class? • equals • compares • both lessThan and greaterThan • compareTo • both compares and equals

29. If s is a String, and s = “no”; is performed, then s • stores the String “no” • references the memory location where “no” is stored • stores the characters ‘n’, ‘o’ • stores an int value that represents the two characters • stores the character ‘n’ and a reference to the memory location where the next character, ‘o’ is stored

30. Assume that you are defining a class and you want to implement an ActionListener. You state addActionListener(this); in your class’ constructor. What does this mean? • The class must import another class which implements ActionListener • The class must define the method actionPerformed • The class must define the method ActionListener • The class must define an inner class called ActionListener • The class must define the method actionPerformed in an inner class named ActionListener

31. A Java program can handle an exception in several different ways. Which of the following is not a way that a Java program could handle an exception? • ignore the exception • handle the exception where it arose using try and catch statements • propagate the exception to another method where it can be handled • throw the exception to a pre-defined Exception class to be handled • all of the above are ways that a Java program could handle an exception

32. An exception can produce a “call stack trace” which lists • the active methods in the order that they were invoked • the active methods in the opposite order that they were invoked • the values of all instance data of the object where the exception was raised • the values of all instance data of the object where the exception was raised and all local variables and parameters of the method where the exception was raised • the name of the exception thrown

33. In order to have some code throw an exception, you would use which of the following reserved words? • throw • throws • try • Throwable • goto

34. JOptionPane is a class that provides GUI • dialog boxes • buttons • output fields • panels and frames • all of the above

35. A listener is an object that • implements any type of interface • is used to accept any form of input • is an inner class to a class that has abstract methods • waits for some action from the user • uses the InputStreamReader class