2014年java复习1(7)

Thread cThread = new Thread(test.new B()); cThread.start(); }

class A extends Thread{ public void run() {

// TODO Auto-generated method stub for(int i=0;i<100;i++){ n++;

System.out.println(\+n); } } }

class B implements Runnable { @Override

public void run() {

// TODO Auto-generated method stub for(int i=0;i<100;i++){ n--;

System.out.println(\+n); } } }

}

//线程同步的话就是 public class Test{

private static int n=100;

public static void main(String[] args){ Test test = new Test(); A a = test.new A(); a.start();

Thread cThread = new Thread(test.new B()); cThread.start(); }

class A extends Thread{ public void run() {

// TODO Auto-generated method stub for(int i=0;i<100;i++){ synchronized(Test.class){ n++;

System.out.println(\+n); } } }

}

class B implements Runnable { @Override

public void run() {

// TODO Auto-generated method stub for(int i=0;i<100;i++){ synchronized(Test.class){ n--;

System.out.println(\+n); } } } } }

—————————————–Part II，总计30分————————————————–

一、选择题(共7题，每题2分，共14分) 1.下面哪个是java的关键字 B A NULL B new C instanceOf

D wend

2.下面语句哪个是正确的 A char s=’abc’; B long l=oxfff; C float f=0.45; D double d =0.8E-3;

3.public class ExampleStringBuffer {

public static void main(String[] args) {

StringBuffer sb = new StringBuffer(“mytest”); System.out.println(“buffer=” + sb); System.out.println(“length=” + sb.length()); } }

程序的运行结果中在“length=”后输出的值是 B A 10 B 6 C 20 D 30

4.在下列的整数数据类型中，需要内存空间最小的是 D A short B long

C int D byte

5. public class MyFor {

static boolean out(char input){ System.out.print(input); return true; }

public static void main(String arg[]){ int i=0;

for(out(‘A’);out(‘B’)&&i<2;out(‘C’)){ i++; out(‘D’); } } }

程序的运行结果是 A A ABDCBDCB B ABCDABCD C 程序编译时出错 D 程序运行时异常

6.在Eclipse中程序代码自动排版的热键是：C