Introduction to Java Programming, Seventh Edition, Y. Daniel Liang
Chapter 5 Methods
Sections 5.2 Creating a Method
1
Suppose your method does not return any value, which of the following keywords can be used as a return type?
A.
void
B.
int
C.
double
D.
public
E.
None of the above
2
The signature of a method consists of ____________.
A.
method name
B.
method name and parameter list
C.
return type, method name, and parameter list
D.
parameter list
3
All Java applications must have a method __________.
A.
public static Main(String[] args)
B.
public static Main(String args[])
C.
public static void main(String[] args)
D.
public void main(String[] args)
E.
public static main(String[] args)
Sections 5.3 Calling a Method
4
Arguments to methods always appear within __________.
A.
brackets
B.
parentheses
C.
curly braces
D.
quotation marks
5
Does the return statement in the following method cause compile errors?
public static void main(String[] args) {
int max = 0;
if (max != 0)
System.out.println(max);
else
return;
}
A.
Yes
B.
No
6
Does the method call in the following method cause compile errors?
public static void main(String[] args) {
Math.pow(2, 4);
}
A.
Yes
B.
No
7
Each time a method is invoked, the system stores parameters and local variables in an area of memory, known as _______, which stores elements in last-in first-out fashion.
A.
a heap
B.
storage area
C.
a stack
D.
an array
Sections 5.4 void Method Example
8
Which of the following should be declared as a void method?
A.
Write a method that prints integers from 1 to 100.
B.
Write a method that returns a random integer from 1 to 100.
C.
Write a method that checks whether current second is an integer from 1 to 100.
D.
Write a method that converts an uppercase letter to lowercase.
Sections 5.5 Passing Parameters by Values
9
When you invoke a method with a parameter, the value of the argument is passed to the parameter. This is referred to as _________.
A.
method invocation
B.
pass by value
C.
pass by reference
D.
pass by name
10
Suppose
static void nPrint(String message, int n) {
while (n > 0) {
System.out.print(message);
n--;
}
}
What is the printout of the call nPrint('a', 4)?
A.
aaaaa
B.
aaaa
C.
aaa
D.
invalid call
11
Suppose
static void nPrint(String message, int n) {
while (n > 0) {
System.out.print(message);
n--;
}
}
What is k after invoking nPrint("A message", k)?
int k = 2;
nPrint("A message", k);
A.
0
B.
1
C.
2
D.
3
Section 5.7 Overloading Methods
12
Analyze the following code:
public class Test {
public static void main(String[] args) {
System.out.println(xMethod(5, 500L));
}
public static int xMethod(int n, long l) {
System.out.println("int, long");
return n;
}
public static long xMethod(long n, long l) {
System.out.println("long, long");
return n;
}
}
A.
The program displays int, long followed by 5.
B.
The program displays long, long followed by 5.
C.
The program runs fine but displays things other than 5.
D.
The program does not compile because the compiler cannot distinguish which xmethod to invoke.
13
Analyze the following code:
class Test {
public static void main(String[] args) {
System.out.println(xmethod(5));
}
public static int xmethod(int n, long t) {
System.out.println("int");
return n;
}
public static long xmethod(long n) {
System.out.println("long");
return n;
}
}
A.
The program displays int followed by 5.
B.
The program displays long followed by 5.
C.
The program runs fine but displays things other than 5.
D.
The program does not compile because the compiler cannot distinguish which xmethod to invoke.
14
Analyze the following code.
public class Test {
public static void main(String[] args) {
System.out.println(max(1, 2));
}
public static double max(int num1, double num2) {
System.out.println("max(int, double) is invoked");
if (num1 > num2)
return num1;
else
return num2;
}
public static double max(double num1, int num2) {
System.out.println("max(double, int) is invoked");
if (num1 > num2)
return num1;
else
return num2;
}
}
A.
The program cannot compile because you cannot have the print statement in a non-void method.
B.
The program cannot compile because the compiler cannot determine which max method should be invoked.
C.
The program runs and prints 2 followed by "max(int, double)" is invoked.
D.
The program runs and prints 2 followed by "max(double, int)" is invoked.
E.
The program runs and prints "max(int, double) is invoked" followed by 2.
15
Analyze the following code.
public class Test {
public static void main(String[] args) {
System.out.println(m(2));
}
public static int m(int num) {
return num;
}
public static void m(int num) {
System.out.println(num);
}
}
A.
The program has a compile error because the two methods m have the same signature.
B.
The program has a compile error because the second m method is defined, but not invoked in the main method.
C.
The program runs and prints 2 once.
D.
The program runs and prints 2 twice.
Section 5.8 The Scope of Variables
16
A variable defined inside a method is referred to as __________.
A.
a global variable
B.
a method variable
C.
a block variable
D.
a local variable
17
What is k after the following block executes?
{
int k = 2;
nPrint("A message", k);
}
System.out.println(k);
A.
0
B.
1
C.
2
D.
k is not defined outside the block. So, the program has a compile error
Section 5.9 The Math Class
18
The client can use a method without knowing how it is implemented. The details of the implementation are encapsulated in the method and hidden from the client who invokes the method. This is known as __________.
A.
information hiding
B.
encapsulation
C.
method hiding
D.
simplifying method
19
Which of the following is a possible output from invoking Math.random()?
A.
3.43
B.
0.5
C.
0.0
D.
1.0
20
What is Math.round(3.6)?
A.
3.0
B.
3
C.
4
D.
4.0
21
What is Math.rint(3.6)?
A.
3.0
B.
3
C.
4.0
D.
5.0
22
What is Math.rint(3.5)?
A.
3.0
B.
3
C.
4
D.
4.0
E.
5.0
23
What is Math.ceil(3.6)?
A.
3.0
B.
3
C.
4.0
D.
5.0
24
What is Math.floor(3.6)?
A.
3.0
B.
3
C.
4
D.
5.0
Section 5.10 Case Study: Generating Random Characters
25
(int)(Math.random() * (65535 + 1)) returns a random number __________.
A.
between 1 and 65536
B.
between 1 and 65535
C.
between 0 and 65535
D.
between 0 and 65536
26
(int)('a' + Math.random() * ('z' - 'a' + 1)) returns a random number __________.
A.
between 0 and (int)'z'
B.
between (int)'a' and (int)'z'
C.
between 'a' and 'z'
D.
between 'a' and 'y'
27
(char)('a' + Math.random() * ('z' - 'a' + 1)) returns a random character __________.
A.
between 'a' and 'z'
B.
between 'a' and 'y'
C.
between 'b' and 'z'
D.
between 'b' and 'y'
28
Which of the following is the best for generating random integer 0 or 1?
A.
(int)Math.random()
B.
(int)Math.random() + 1
C.
(int)(Math.random() + 0.5)
D.
(int)(Math.random() + 0.2)
E.
(int)(Math.random() + 0.8)
Section 5.11 Method Abstraction and Stepwise Refinement
29
__________ is to implement one method in the structure chart at a time from the top to the bottom.
A.
Bottom-up approach
B.
Top-down approach
C.
Bottom-up and top-down approach
D.
Stepwise refinement
30
__________ is a simple but incomplete version of a method.
A.
A stub
B.
A main method
C.
A non-main method
D.
A method developed using top-down approach