TeStA
TeStB
编译失败
运行时抛出异常
第1题:
执行下列代码之后,输出的结果为______。 public class ex27 { public static void main(String[] args) { iht x=7; int y=15; boolean bb=(127|x)>7&&(-128∧y)<15; System.out. println(bb); } }
A.true
B.0
C.1
D.false
第2题:
public class TestA{ public void methodA() throws IOException{ //…… } } public class TestB extends TestA{ public void methodA() throws EOFException{ //…… } } public class TestC extends TestA{ public void methodA() throws Exception{ //…… } } 当编译类TestC的时候,结果是哪项?()
第3题:
interface Data { public void load(); } abstract class Info { public abstract void load(); } Which class correctly uses the Data interface and Info class?()
第4题:
public class A extends Thread { A() { setDaemon(true); } public void run() { (new B()).start(); try { Thread.sleep(60000); } catch (InterruptedException x) {} System.out.println(“A done”); } class B extends Thread { public void run() { try { Thread.sleep(60000); } catch (InterruptedException x) {} System.out.println(“B done”); } } public static void main(String[] args) { (new A()).start(); } } What is the result?()
第5题:
现有: interface Data {public void load();} abstract class Info {public abstract void load();} 下列类定义中正确使用Data和Info的是哪项?()
第6题:
现有 public class Parentt public void change (int x){) ) public class Child extends Parent{ //覆盖父类change方法 } 下列哪个声明是正确的覆盖了父类的change方法?()
第7题:
void run()
public void run()
public void start()
void run(int priority)
public void run(int priority)
public void start(int priority)
第8题:
public class Employee extends Info implements Data { public void load() { /*do something*/ } }
public class Employee implements Info extends Data { public void load() { /*do something*/ } }
public class Employee extends Info implements Data { public void load() { /*do something */ } public void Info.load() { /*do something*/ } }
public class Employee implements Info extends Data { public void Data.load() { /*dsomething */ } public void load() { /*do something */ } }
public class Employee implements Info extends Data { public void load() { /*do something */ } public void Info.load(){ /*do something*/ } }
public class Employee extends Info implements Data{ public void Data.load() { /*do something*/ } public void Info.load() { /*do something*/ } }
第9题:
protected void change (int x){}
public void change(int x, int y){}
public void change (int x){}
public void change (String s){}
第10题:
0
1
2
3
第11题:
TeStA
TeStB
编译失败
运行时抛出异常
第12题:
new Thread() { public void run() { doStuff(); } }
new Thread() { public void start() { doStuff(); } }
new Thread() { public void start() { doStuff(); } } .run();
new Thread() { public void run() { doStuff(); } } .start();
new Thread(new Runnable() { public void run() { doStuff(); } } ).run();
new Thread(new Runnable() { public void run() { doStuff(); } }).start();
第13题:
class MyThread extends Thread { public void run() { System.out.println(“AAA”); } public void run(Runnable r) { System.out.println(“BBB”); } public static void main(String[] args) { new Thread(new MyThread()).start(); } } What is the result?()
第14题:
1. class TestA { 2. TestB b; 3. TestA() { 4. b = new TestB(this); 5. } 6. } 7. class TestB { 8. TestA a; 9. TestB(TestA a) { 10. this.a = a; 11. } 12. } 13. class TestAll { 14. public static void main (String args[]) { 15. new TestAll().makeThings(); 16. // ...code continues on 17. } 18. void makeThings() { 19. TestA test = new TestA(); 20. } 21. } Which two statements are true after line 15, before main completes?()
第15题:
class TestA { public void start() { System.out.println(”TestA”); } } public class TestB extends TestA { public void start() { System.out.println(”TestB”); } public static void main(String[] args) { ((TestA)new TestB()).start(); } } What is the result?()
第16题:
Which method must be defined by a class implementing the java.lang.Runnable interface? ()
第17题:
现有: class TestA { public void start() { System.out.println("TestA"); } } public class TestB extends TestA { public void start() { System.out.println("TestB"); } public static void main (string[] args) ( ((TestA)new TestB()).start(); ) } 运行结果是哪项?()
第18题:
Which two code fragments will execute the method doStuff() in a separate thread?()
第19题:
public class Employee implements Info extends Data { public void load(){/*dosomething*/} }
public class Employee extends Inf.implements Data{ public void load() {/*do something*/} }
public class Empl.yee implements Inf extends Data{ public void Data.1oad(){* do something*/} public void load(){/*do something*/} }
public class Employee extends Inf implements Data { public void Data.1oad() {/*do something*/) public void info.1oad(){/*do something*/} }
第20题:
new Thread() {public void run() { doStuff(); }};
new Thread() {public void start() { doStuff(); }};
new Thread() {public void start() { doStuff(); }}.run();
new Thread() {public void run() { doStuff(); }}.start();
new Thread(new Runnable() {public void run() { doStuff(); }}).start();
第21题:
Compilation will fail.
Compilation will succeed and the program will print “0”
Compilation will succeed and the program will print “1”
Compilation will succeed and the program will print “2”
第22题:
正常
编译错误
运行错误
以上都不对
第23题:
TestA
TestB
Compilation fails.
An exception is thrown at runtime.
第24题:
1
2
3
4