Java练习题1（有答案）(9)

} } B:

public class Test { public Test() { java.util.Date date = new java.util.Date(); } } 1、 A. 2、 B.

3、 Neither 答案 1 2 第 103题 You should add the static keyword in the place of ? in Line ________ in the following code: 1 public class Test {

2 private int age;

3

4 public ? int square(int n) { 5 return n * n; 6 } 7

8 public ? int getAge() { 9 } 10}

1、 in line 4 2、 in line 8

3、 in both line 4 and line 8

4、 none 答案 1 第 104题 Analyze the following code. public class Test { public static void main(String[] args) { int n = 2; xMethod(n); System.out.println(\ } void xMethod(int n) { n++; } }

1、 The code has a compile error because xMethod does not return a value.

2、 The code has a compile error because xMethod is not declared static. 3、 The code prints n is 1.

4、 The code prints n is 2.

5、 The code prints n is 3. 答案 2 第 105题 What is the printout of the second println statement in the main method? public class Foo { int i; static int s;

public static void main(String[] args) { Foo f1 = new Foo();

System.out.println(\ Foo f2 = new Foo();

System.out.println(\ Foo f3 = new Foo();

System.out.println(\ } public Foo() { i++; s++; } }

1、 f2.i is 1 f2.s is 1 2、 f2.i is 1 f2.s is 2 3、 f2.i is 2 f2.s is 2

4、 f2.i is 2 f2.s is 1 答案 2 第 106题 What is the printout of the third println statement in the main method? public class Foo { int i; static int s;

public static void main(String[] args) { Foo f1 = new Foo();

System.out.println(\ Foo f2 = new Foo();

System.out.println(\ Foo f3 = new Foo();

System.out.println(\ } public Foo() { i++; s++; } }

1、 f3.i is 1 f3.s is 1 2、 f3.i is 1 f3.s is 2 3、 f3.i is 1 f3.s is 3 4、 f3.i is 3 f3.s is 1

5、 f3.i is 3 f3.s is 3 答案 3 第 107题 Analyze the following code: public class Test {

public static void main(String args[]) { NClass nc = new NClass(); nc.t = nc.t++; } } class NClass { int t;

private NClass() { } }

1、 The program has a compilation error because the NClass class has a private constructor.

2、 The program does not compile because the parameter list of the main method is wrong.

3、 The program compiles, but has a runtime error because t has no initial value.

4、 The program compiles and runs fine. 答案 1 第 108题 Analyze the following code:

public class Test { private int t; public static void main(String[] args) { int x; System.out.println(t); } } …… 此处隐藏：316字，全部文档内容请下载后查看。喜欢就下载吧 ……