JAVA面试题大全（含答案）(9)

} }

public class Test{

public static void main(String[] args){

A ab = new B ();

ab = new B (); } }

解答：abxyxy

101、下列代码的输出结果是什么？

public class MyFor {

public static void main (String argv[]){

int i; int j;

outer:for(i=1;i<3;i++)

inner:for(j=1;j<3;j++){

if (j==2) continue outer;

System.out .println(“Value for i=”+i+” } } }

解答：Value for i=1 Value for j=1

Value for i=2 Value for j=1

Value for j=”+j);

102、查看下面的代码，写出可以使程序正常执行的修改方法

1.public class MyClass {

2.static String s1;

3. String s2;

4. public static void main(String args[]) {

5. String s3;

6. System.out.println(“s1 =” + s1);

7. System.out.println(“s2 =” + s2);

8. System.out.println(“s3 =” + s3); 9. } 10.}

解答：删除第8行或者将第6行改为String s3 = “”;

103、为了显示myStr = 23 这样的结果，写出在控制台输入的命令

public class MyClass {

public static void main(String args[]) {

String s1 = args[0];

String s2 = args[1];

String myStr = args[2];

System.out.printin(“myStr =” + s2 + myStr); } }

解答：java MyClass 1 2 3 4

104、写出下面代码的执行结果

public class MyClass {

static void aMethod(StringBuffer sf1, StringBuffer sf2) {

sf1.append(sf2);

sf2 = sf1; }

public static void main(String[] args){

StringBuffer sf1 = new StringBuffer(“A”);

StringBuffer sf2 = new StringBuffer(“B”);

aMethod(sf1,sf2);

System.out .println(sf1+ “:”+sf2); } }

解答：AB:B

105、第3行中生成的object在第几行执行后成为garbage collection的对象？

1.public class MyClass {

2. public StringBuffer aMethod() {

3. StringBuffer sf = new StringBuffer(“Hello”);

4. StringBuffer[] sf_arr = new StringBuffer[1];

5. sf_arr[0] = sf;

6. sf = null;

7. sf_arr[0] = null;

8. return sf; 9. } 10.}

解答：第7行

106、写出执行下面的代码后的结果

public class MyClass {

public static void main(String args[]) {

java.util.Vector v1 = new java.util.Vector();

v1.addElement(“Hello”);

v1.addElement(new Float(3.14f));

v1.addElement(10);

System.out.println(v1.elementAt(0) + “:” } }

解答：Hello : 3.14 : 10

107、写出执行下面代码后的正确结果

interface MyDB {

public void getConnection(); }

class MyDBDriver implements MyDB {

public void getConnection() {

System.out.println(“getConnection()”);

+ v1.elementAt(1) + :”+ v1.elementAt(2)); “ } }

public class MyClass {

public static void aMethod(MyDB db) {

db.getConnection(); }

public static void main(String args[]) {

MyDBDriver db_driver = new MyDBDriver();

aMethod(db_driver); } }

解答：getConnection()

108、下列程序运行的结果是

class A {

class Dog {

private String name;

private int age;

private int step;

Dog(String s, int a) {

name = s;

age = a;

step = 0;