发布时间 : 星期二 文章面向对象编程基础习题及答案更新完毕开始阅读
double, but assigned with integer value 0.
B. The program never stops because d is always 0.1 inside the loop. C. The program may not stop because of the phenomenon referred
to as numerical inaccuracy for operating with floating-point numbers. D. After the loop, sum is 0 + 0.1 + 0.2 + 0.3 + ... + 1.9 61. What is y after the following for loop statement is executed?
int y = 0;
for (int i = 0; i < 10; ++i) {
y += 1; }
A. 9 B. 10 C. 11
D. 12
E. None of the above.
62. What balance after the following code is executed?
int balance = 10; while (balance >= 1) {
if (balance < 9) continue; balance = balance - 9; }
A. -1 B. 0 C. 1 D. 2
E. The loop does not end
63. What is the value of balance after the following code is executed?
int balance = 10;
while (balance >= 1) {
if (balance < 9) break; balance = balance - 9; }
A. –1 B. 0 C. 1
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D. 2
E. None of the above 64. What is x after evaluating
x = (2 > 3) ? 2 : 3;
A. 2 B. 3 C. 4
D. None of the above
65. 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
66. A variable that is declared inside a method is called ________ variable.
A. a static B. an instance C. a local
D. a global E. a class
67. Each Java class must contain a main method.
A. true B. false 68. What is (int)Math.random()?
A. 0 B. 1
C. both 0 and 1 are possible D. None of the above 69. 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); }
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}
A. The program has a syntax error because the two methods m have
the same signature.
B. The program has a syntax 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. 70. Analyze the following code:
class Test {
public static void main(String[] args) { System.out.println(xMethod((double)5)); }
public static int xMethod(int n) { System.out.println(\ return n; }
public static long xMethod(long n) { System.out.println(\ 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 given in
A and B. D. The program does not compile. E. None of the above. 71. 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(\ return n; }
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public static long xMethod(long n, long l) { System.out.println(\ 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 given in
a and b.
D. The program does not compile because the compiler cannot distinguish which xmethod to invoke.
72. You may have a return statement in a void method.
A. true B. false
Note: Questions 73–75 are based on the following method:
static void nPrint(String message, int n) { while (n > 0) {
System.out.print(message); n--; } }
73. What is the printout of the call nPrint(\
A. aaaaa B. aaaa C. aaa
D. invalid call
74. What is k after invoking nPrint(“A message”, k+1)?
int k = 2;
nPrint(\ A. 0 B. 1 C. 2
D. 3
E. None of the above.
75. Analyze the following code.
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