1)
</td>
<td colspan="3" valign="top" width="661">
<p align="left">以下选项中是对一个Java源文件进行正确编译的语句是( A?? )(选择一项)
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td valign="top" width="50">
<p align="left">?
</td>
<td colspan="2" valign="top" width="611">
<p align="left">?
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td valign="top" width="50">
<p align="left">A.
</td>
<td colspan="2" valign="top" width="611">
javac Test.java
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td valign="top" width="50">
<p align="left">B.
</td>
<td colspan="2" valign="top" width="611">
<p align="left">javac Test
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td valign="top" width="50">
<p align="left">C.
</td>
<td colspan="2" valign="top" width="611">
java Test
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td valign="top" width="50">
<p align="left">D.
</td>
<td colspan="2" valign="top" width="611">
java Test.class
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">2)
</td>
<td colspan="3" valign="top" width="661">
<p align="left">以下选项中属于合法的Java标识符的是(CD?? ?)。(选择两项)
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">?
</td>
<td valign="top" width="607">
<p align="left">?
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">A.
</td>
<td valign="top" width="607">
<p align="left">public
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">B.
</td>
<td valign="top" width="607">
3num
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">C.
</td>
<td valign="top" width="607">
<p align="left">name
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">D.
</td>
<td valign="top" width="607">
<p align="left">_age
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">3)
</td>
<td colspan="3" valign="top" width="661">
以下代码的执行结果是(
?B?
)。(选择一项)
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="3" valign="top" width="661">
<p align="left">boolean m = true;
<p align="left">if(m = false){
<p align="left">??? System.out.println("false");
<p align="left">}else{
<p align="left">??? System.out.println("true");
<p align="left">}
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">?
</td>
<td valign="top" width="607">
<p align="left">?
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">A.
</td>
<td valign="top" width="607">
<p align="left">false
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">B.
</td>
<td valign="top" width="607">
<p align="left">true
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">C.
</td>
<td valign="top" width="607">
<p align="left">编译错误
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">D.
</td>
<td valign="top" width="607">
<p align="left">无结果
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">4)
</td>
<td colspan="3" valign="top" width="661">
<p align="left">以下do-while循环代码的执行结果是( A??
)。(选择一项)
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="3" valign="top" width="661">
<p align="left">int a=0;
<p align="left">int c=0;
<p align="left">do{
<p align="left">??? --c;
<p align="left">??? a=a-1;
<p align="left">}while(a>0);
<p align="left">System.out.println(a+"? "+c);
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">?
</td>
<td valign="top" width="607">
<p align="left">?
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">A.
</td>
<td valign="top" width="607">
<p align="left">-1? -1
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">B.
</td>
<td valign="top" width="607">
<p align="left">死循环
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">C.
</td>
<td valign="top" width="607">
<p align="left">-1? -2
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">D.
</td>
<td valign="top" width="607">
<p align="left">-1? 0
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">5)
</td>
<td colspan="3" valign="top" width="661">
<p align="left">while循环和do-while循环的区别是( D?? )。(选择一项)
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">?
</td>
<td valign="top" width="607">
<p align="left">?
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">A.
</td>
<td valign="top" width="607">
没有区别,这两个结构在任何情况下效果一样
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">B.
</td>
<td valign="top" width="607">
<p align="left">while循环比do-while循环执行效率高
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">C.
</td>
<td valign="top" width="607">
<p align="left">while循环是先循环后判断,所以循环体至少被执行一次
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">D.
</td>
<td valign="top" width="607">
do-while循环是先循环后判断,所以循环体至少被执行一次
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">6)
</td>
<td colspan="3" valign="top" width="661">
<p align="left">分析下面的Java多重循环代码片段,编译运行后的输出结果是( D ??)。(选择一项)
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="3" valign="top" width="661">
<p align="left">for (int i = 0; i < 6; i++) {
<p align="left">??? int k = ++i;
<p align="left">??? while (k < 5) {
<p align="left">?????? System.out.print(i);
<p align="left">?????? break;
<p align="left">??? }
<p class="CX">}
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">?
</td>
<td valign="top" width="607">
<p align="left">?
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">A.
</td>
<td valign="top" width="607">
024
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">B.
</td>
<td valign="top" width="607">
<p align="left">02
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">C.
</td>
<td valign="top" width="607">
<p align="left">123
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">D.
</td>
<td valign="top" width="607">
<p align="left">13
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">7)
</td>
<td colspan="3" valign="top" width="661">
<p align="left">以下关于方法调用的代码的执行结果是( ??B )。(选择一项)
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="3" valign="top" width="661">
<p align="left">public class Test {
<p align="left">??? public static void main(String args[]) {
<p align="left">?????? int i = 99;
<p align="left">?????? mb_operate(i);
<p align="left">?????? System.out.print(i + 100);
<p align="left">??? }
<p align="left">??? static void mb_operate(int i) {
<p align="left">?????? i += 100;
<p align="left">??? }
<p align="left">}
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">?
</td>
<td valign="top" width="607">
<p align="left">?
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">A.
</td>
<td valign="top" width="607">
99
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">B.
</td>
<td valign="top" width="607">
199
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">C.
</td>
<td valign="top" width="607">
299
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">D.
</td>
<td valign="top" width="607">
99100
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">8)
</td>
<td colspan="3" valign="top" width="661">
<p align="left">以下关于继承条件下构造方法执行过程的代码的执行结果是( ?A? )。(选择一项)
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="3" valign="top" width="661">
<p align="left">class Person {???
<p align="left">??? public Person() {
<p align="left">?????? System.out.println("execute Person()");1
<p align="left">??? }
<p align="left">}
<p align="left">class Student extends Person {?
<p align="left">??? public Student() {??????
<p align="left">?????? System.out.println("execute Student() ");2
<p align="left">??? }??
<p align="left">}
<p align="left">class PostGraduate extends Student {??
<p align="left">??? public PostGraduate() {?
<p align="left">?????? System.out.println("execute
PostGraduate()");3
<p align="left">??? }??
<p align="left">}
<p align="left">public class TestInherit {
<p align="left">??? public static void main(String[] args) {
<p align="left">?????? new PostGraduate();?????
<p align="left">??? }
<p align="left">}
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">?
</td>
<td valign="top" width="607">
<p align="left">?
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">A.
</td>
<td valign="top" width="607">
<p align="left">execute Person()
<p align="left">execute Student()
<p align="left">execute PostGraduate()
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">B.
</td>
<td valign="top" width="607">
<p align="left">execute PostGraduate()
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">C.
</td>
<td valign="top" width="607">
<p align="left">execute PostGraduate()
<p align="left">execute Student()
<p align="left">execute Person()
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">D.
</td>
<td valign="top" width="607">
<p align="left">没有结果输出
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">9)
</td>
<td colspan="3" valign="top" width="661">
<p align="left">以下语句中关于Java构造方法的说法错误的是( ?B? )。(选择一项)
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">?
</td>
<td valign="top" width="607">
<p align="left">?
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">A.
</td>
<td valign="top" width="607">
构造方法的作用是为创建对象进行初始化工作,比如给成员变量赋值
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">B.
</td>
<td valign="top" width="607">
<p align="left">一个Java类可以没有构造方法,也可以提供1个或多个构造方法
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">C.
</td>
<td valign="top" width="607">
<p align="left">构造方法与类同名,不能书写返回值类型
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">D.
</td>
<td valign="top" width="607">
<p align="left">构造方法的第一条语句如果是super(),则可以省略,该语句作用是调用父类无参数的构造方法
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">10)
</td>
<td colspan="3" valign="top" width="661">
<p align="left">以下关于this和super关键字的说法错误的是(? BD? )。(选择二项)
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">?
</td>
<td valign="top" width="607">
<p align="left">?
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">A.
</td>
<td valign="top" width="607">
<p align="left">this关键字指向当前对象自身,super关键字指向当前对象的直接父类
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">B.
</td>
<td valign="top" width="607">
<p align="left">在main方法中可以存在this或super关键字,但不能同时存在。
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">C.
</td>
<td valign="top" width="607">
<p align="left">this和super关键字都可以访问成员属性,成员方法和构造方法
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">D.
</td>
<td valign="top" width="607">
<p align="left">在一个类的构造方法中可以同时使用this和super来调用其他构造方法
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">11)
</td>
<td colspan="3" valign="top" width="661">
<p align="left">以下选项中可以使成员变量m 被函数fun()直接访问的是( ?C ?)。(选择一项)
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="3" valign="top" width="661">
<p align="left">class Test {
<p align="left">??? private int m;
<p align="left">??? public static void fun() {?????
<p align="left">?????? System.out.println(m);
<p align="left">??? }
<p align="left">}
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">?
</td>
<td valign="top" width="607">
<p align="left">?
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">A.
</td>
<td valign="top" width="607">
<p align="left">将private
int m 改为protected
int m
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">B.
</td>
<td valign="top" width="607">
<p align="left">将private
int m 改为 public
int m
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">C.
</td>
<td valign="top" width="607">
<p align="left">将private
int m 改为 static
int m
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">D.
</td>
<td valign="top" width="607">
<p align="left">将private
int m 改为 int m
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">12)
</td>
<td colspan="3" valign="top" width="661">
<p align="left">Person类和Test类的代码如下所示,则代码中的错误语句是( C?? )。(选择一项)
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="3" valign="top" width="661">
<p align="left">public class
Person {
<p align="left">??? public String name;
<p align="left">??? public Person(String
name) {
<p align="left">?????? this.name = name;
<p align="left">??? }
<p align="left">}
<p align="left">public class
Test {
<p align="left">??? public static void
main(String[] args) {
<p align="left">??????? final Person person
= new Person("欧欧");
<p align="left">??????? person.name = "美美";
<p align="left">??????? person = new
Person("亚亚");
<p align="left">??? }
<p align="left">}
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">?
</td>
<td valign="top" width="607">
<p align="left">?
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">?
<p align="left">A.
</td>
<td valign="top" width="607">
<p align="left">?
<p align="left">final Person person = new Person("欧欧");
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">B.
</td>
<td valign="top" width="607">
<p align="left">person.name = "美美";
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">C.
</td>
<td valign="top" width="607">
<p align="left">person = new Person("亚亚");
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">D.
</td>
<td valign="top" width="607">
<p align="left">没有错误
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">13)
</td>
<td colspan="3" valign="top" width="661">
<p align="left">以下关于异常的代码的执行结果是( ?C? )。(选择一项)
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="3" valign="top" width="661">
<p align="left">public class Test {
<p align="left">??? public static void main(String args[]) {
<p align="left">?????? try {
<p align="left">?????????? System.out.println("try");????????
<p align="left">?????????? return;
<p align="left">?????? } catch(Exception e){
<p align="left">?????????? System.out.println("catch");
<p align="left">?????? }finally {
<p align="left">?????????? System.out.println("finally");
<p align="left">?????? }
<p align="left">??? }
<p align="left">}
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">?
</td>
<td valign="top" width="607">
<p align="left">?
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">A.
</td>
<td valign="top" width="607">
<p align="left">try
<p align="left">catch
<p align="left">finally
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">B.
</td>
<td valign="top" width="607">
<p align="left">catch
<p align="left">finally
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">C.
</td>
<td valign="top" width="607">
<p align="left">try
<p align="left">finally
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">D.
</td>
<td valign="top" width="607">
<p align="left">try
<p align="left">?
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">14)
</td>
<td colspan="3" valign="top" width="661">
<p align="left">以下关于String类的代码的执行结果是( B ??)。(选择一项)
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="3" valign="top" width="661">
<p align="left">public class Test2 {
<p align="left">??? public static void
main(String args[]) {
<p align="left">??????? String s1 = new
String("bjsxt");
<p align="left">??????? String s2 = new
String("bjsxt");
<p align="left">??????? if (s1 == s2)
<p align="left">??????????? System.out.println("s1
== s2");
<p align="left">??????? if (s1.equals(s2))
<p align="left">??????????? System.out.println("s1.equals(s2)");
<p align="left">??? }
<p align="left">}
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">?
</td>
<td valign="top" width="607">
<p align="left">?
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">A.
</td>
<td valign="top" width="607">
<p align="left">s1 == s2
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">B.
</td>
<td valign="top" width="607">
<p align="left">s1.equals(s2)
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">C.
</td>
<td valign="top" width="607">
<p align="left">s1 == s2
<p align="left">s1.equals(s2)
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">D.
</td>
<td valign="top" width="607">
<p align="left">以上都不对
<p align="left">?
<p align="left">?
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">15)
</td>
<td colspan="3" valign="top" width="661">
<p align="left">以下关于StringBuffer类的代码的执行结果是( ?D? )。(选择一项)
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="3" valign="top" width="661">
<p align="left">public class
TestStringBuffer {
<p align="left">??? public static void
main(String args[]) {
<p align="left">?????? StringBuffer a = new
StringBuffer("A");
<p align="left">?????? StringBuffer b = new
StringBuffer("B");
<p align="left">?????? mb_operate(a,b);
<p align="left">?????? System.out.println(a
- "." + b);
<p align="left">??? }
<p align="left">??? static void
mb_operate(StringBuffer x,StringBuffer y) {
<p align="left">?????? x.append(y);
<p align="left">?????? y = x;
<p align="left">??? }
<p align="left">}
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">?
</td>
<td valign="top" width="607">
<p align="left">?
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">A.
</td>
<td valign="top" width="607">
A.B?
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">B.
</td>
<td valign="top" width="607">
A.A
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">C.
</td>
<td valign="top" width="607">
<p align="left">AB.AB
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">D.
</td>
<td valign="top" width="607">
AB.B
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">16)
</td>
<td colspan="3" valign="top" width="661">
<p align="left">以下选项中能够正确创建一个数组的是( AD ??)。(选择二项)
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">?
</td>
<td valign="top" width="607">
<p align="left">?
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">A.
</td>
<td valign="top" width="607">
float []f[] = new float[6][6];
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">B.
</td>
<td valign="top" width="607">
float f[][] = new float[][];
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">C.
</td>
<td valign="top" width="607">
<p align="left">float [6][]f = new
float[6][6];
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">D.
</td>
<td valign="top" width="607">
float [][]f = new float[6][];
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">17)
</td>
<td colspan="3" valign="top" width="661">
<p align="left">以下选项中关于int和Integer的说法错误的是( ?BD)。(选择二项)
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">?
</td>
<td valign="top" width="607">
<p align="left">?
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">A.
</td>
<td valign="top" width="607">
int是基本数据类型,Integer是int的包装类,是引用数据类型
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">B.
</td>
<td valign="top" width="607">
int的默认值是0,Integer的默认值也是0
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">C.
</td>
<td valign="top" width="607">
<p align="left">Integer可以封装了属性和方法提供更多的功能
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">D.
</td>
<td valign="top" width="607">
Integer i=5;该语句在JDK1.5之后可以正确执行,使用了自动拆箱功能
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">18)
</td>
<td colspan="3" valign="top" width="661">
<p align="left">以下选项中关于Java集合的说法错误的是( AC ??)。(选择二项)
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">?
</td>
<td valign="top" width="607">
<p align="left">?
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">A.
</td>
<td valign="top" width="607">
<p align="left">List接口和Set接口是Collections接口有两个子接口
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">B.
</td>
<td valign="top" width="607">
<p align="left">List接口中存放的元素具有有序,不唯一的特点
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">C.
</td>
<td valign="top" width="607">
<p align="left">Set接口中存放的元素具有无序,不唯一的特点
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">D.
</td>
<td valign="top" width="607">
<p align="left">Map接口存放的是映射信息,每个元素都是一个键值对
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">19)
</td>
<td colspan="3" valign="top" width="661">
<p align="left">以下代码的执行结果是(B )。(选择一项)
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="3" valign="top" width="661">
<p align="left">Set
s=new HashSet();
<p align="left">s.add("abc");
<p align="left">s.add("abc");
<p align="left">s.add("abc");
<p align="left">s.add("abcd");
<p align="left">System.out.println(s.size());
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">?
</td>
<td valign="top" width="607">
<p align="left">?
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">A.
</td>
<td valign="top" width="607">
<p align="left">1
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">B.
</td>
<td valign="top" width="607">
<p align="left">2
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">C.
</td>
<td valign="top" width="607">
<p align="left">3
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">D.
</td>
<td valign="top" width="607">
<p align="left">4
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">20)
</td>
<td colspan="3" valign="top" width="661">
<p align="left">下面集合类中属于非线程安全,且结构采用了哈希表的是( C )。(选择一项)
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">?
</td>
<td valign="top" width="607">
<p align="left">?
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">A.
</td>
<td valign="top" width="607">
<p align="left">Vector
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">B.
</td>
<td valign="top" width="607">
<p align="left">ArrayList
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">C.
</td>
<td valign="top" width="607">
<p align="left">HashMap
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">D.
</td>
<td valign="top" width="607">
<p align="left">Hashtable
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">21)
</td>
<td colspan="3" valign="top" width="661">
<p align="left">以下选项中关于如下代码的说法正确的是( ?AD)。(选择二项)
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="3" valign="top" width="661">
<p align="left">public class TestBuffered {
<p align="left">??? public static void main(String[] args) throws
IOException {
<p align="left">?????? BufferedReader br =
<p align="left">?????????? new BufferedReader(new
FileReader("d:/bjsxt1.txt"));
<p align="left">?????? BufferedWriter bw =
<p align="left">?????????? new BufferedWriter(new
FileWriter("d:/bjsxt2.txt"));
<p align="left">?????? String str = br.readLine();
<p align="left">?????? while(str !=null){
<p align="left">?????????? bw.write(str);
<p align="left">?????????? bw.newLine();
<p align="left">?????????? str = br.readLine();
<p align="left">?????? }
<p align="left">?????? br.close();
<p align="left">?????? bw.close();??
<p align="left">??? }
<p align="left">}
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">?
</td>
<td valign="top" width="607">
<p align="left">?
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">A.
</td>
<td valign="top" width="607">
<p align="left">该类使用字符流实现了文件复制,将d:/bjsxt1.txt复制为d:/bjsxt2.txt
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">B.
</td>
<td valign="top" width="607">
<p align="left">FileReader和FileWriter是处理流,直接从文件读写数据
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">C.
</td>
<td valign="top" width="607">
<p align="left">BufferedReader和BufferedWriter是节点流,提供缓冲区功能,提高读写效率
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">D.
</td>
<td valign="top" width="607">
<p align="left">readLine()可以读取一行数据,返回值是字符串类型,简化了操作
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">22)
</td>
<td colspan="3" valign="top" width="661">
<p align="left">InputStreamReader是转换流,可以将字节流转换成字符流,是字符流与字节流之间的桥梁。它的实现使用的设计模式是( C? )。(选择一项)
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">?
</td>
<td valign="top" width="607">
<p align="left">?
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">A.
</td>
<td valign="top" width="607">
<p align="left">工厂模式
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">B.
</td>
<td valign="top" width="607">
<p align="left">装饰模式
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">C.
</td>
<td valign="top" width="607">
<p align="left">适配器模式
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">D.
</td>
<td valign="top" width="607">
<p align="left">代理模式
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">23)
</td>
<td colspan="3" valign="top" width="661">
<p align="left">以下选项中可以填写到横线处,让代码正确编译和运行的是( A??
)。(选择一项)
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="3" valign="top" width="661">
<p align="left">public class Test implements Runnable {
<p align="left">??? public static void main(String[] args) {
<p align="left">?????? ___
<p align="left">?????? t.start();
<p align="left">?????? System.out.println("main");
<p align="left">??? }
<p align="left">??? public void run() {
<p align="left">?????? System.out.println("thread1!");
<p align="left">??? }
<p align="left">}
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">?
</td>
<td valign="top" width="607">
<p align="left">?
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">A.
</td>
<td valign="top" width="607">
<p align="left">Thread t = new Thread(new Test());
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">B.
</td>
<td valign="top" width="607">
<p align="left">Test t = new Test();
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">C.
</td>
<td valign="top" width="607">
<p align="left">Thread t = new Test();?????????????
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">D.
</td>
<td valign="top" width="607">
<p align="left">Thread t = new Thread();
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">24)
</td>
<td colspan="3" valign="top" width="661">
<p align="left">在多个线程访问同一个资源时,可以使用( ?A? )关键字来实现线程同步,保证对资源安全访问。(选择一项)
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">?
</td>
<td valign="top" width="607">
<p align="left">?
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">A.
</td>
<td valign="top" width="607">
<p align="left">synchronized
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">B.
</td>
<td valign="top" width="607">
<p align="left">transient
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">C.
</td>
<td valign="top" width="607">
<p align="left">static
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">D.
</td>
<td valign="top" width="607">
<p align="left">yield
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">25)
</td>
<td colspan="3" valign="top" width="661">
<p align="left">以下说法中关于UDP协议的说法正确的是( ?AD? )。(选择二项)
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">?
</td>
<td valign="top" width="607">
<p align="left">?
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">A.
</td>
<td valign="top" width="607">
<p align="left">发送不管对方是否准备好,接收方收到也不确认
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">B.
</td>
<td valign="top" width="607">
<p align="left">面向连接
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">C.
</td>
<td valign="top" width="607">
<p align="left">占用系统资源多、效率低
</td>
</tr>
<tr>
<td valign="top" width="53">
<p align="left">?
</td>
<td colspan="2" valign="top" width="53">
<p align="left">D.
</td>
<td valign="top" width="607">
<p align="left">非常简单的协议,可以广播发送
</td>
</tr>
<tr>
<td width="53">?</td>
<td width="50">?</td>
<td width="3">?</td>
<td width="607">?</td>
</tr>