No statement is required.
import jave.io.*;
include java.io.*;
import jave.io.PrintWriter;
include java.io.PrintWriter;
第1题:
下列程序段的输出是( )。 public class Test { public static void main (String args[ ]) { String ss1 = new String("hello"); String ss2 = new String("hello"); System.out.println(ssl == ss2); System.out.println (ssequals(ss2)); } }
A.true, false
B.true, true
C.false, true
D.false, false
第2题:
public class Base { public static final String FOO = “foo”; public static void main(String[] args) { Base b = new Base(); Sub s = new Sub(); System.out.print(Base.FOO); System.out.print(Sub.FOO); System.out.print(b.FOO); System.out.print(s.FOO); System.out.print(((Base)s).FOO); } } class Sub extends Base {public static final String FOO=bar;} What is the result?()
第3题:
请阅读下面程序 public class ThreadTest { public static void main(String args[]) throws Exception{ int i=0; Hello t=new Hello(); while(true) { System.out.println("Good Moming"+i++); if (i==2 && t.isAlive()) { System. out.println("Main waiting for Hello!"); t.join(); //等待t运行结束 } if(i==5) break;} } } class Hello extends Thread { int i; public void run() { while(true){ System.out.println("Hello"+i++); if (i==5) break;}}} 为使该程序正确执行,下划线处的语句应是
A.t.sleep()
B.t.yield()
C.t.interrupt()
D.t.start()
第4题:
//point X public class foo { public static void main (String[]args) throws Exception { java.io.printWriter out = new java.io.PrintWriter { new java.io.outputStreamWriter (System.out), true; out.printIn(“Hello”); } } } Which statement at PointX on line 1 allows this code to compile and run?()
第5题:
Which statements, when inserted at the indicated position in the following code, will cause a runtime exception when attempting to run the program?() class A {} class B extends A {} class C extends A {} public class Q3ae4 { public static void main(String args[]) { A x = new A(); B y = new B(); C z = new C(); // insert statement here } }
第6题:
Which are syntactically valid statement at// point x?() class Person { private int a; public int change(int m){ return m; } } public class Teacher extends Person { public int b; public static void main(String arg[]){ Person p = new Person(); Teacher t = new Teacher(); int i; // point x } }
第7题:
//point X public class foo ( public static void main (String[]args) throws Exception { printWriter out = new PrintWriter (new java.io.outputStreamWriter (System.out), true; out.printIn(“Hello”); } ) Which statement at PointX on line 1 allows this code to compile and run?()
第8题:
interface A{
int x = 0;
}
class B{
int x =1;
}
class C extends B implements A {
public void pX(){
System.out.println(x);
}
public static void main(String[] args) {
new C().pX();
}
}
错误。在编译时会发生错误(错误描述不同的JVM 有不同的信息,意思就是未明确的
x 调用,两个x 都匹配(就象在同时import java.util 和java.sql 两个包时直接声明Date 一样)。
对于父类的变量,可以用super.x 来明确,而接口的属性默认隐含为 public static final.所以可
以通过A.x 来明确。
第9题:
public class Test { public static void aMethod() throws Exception { try { throw new Exception(); } finally { System.out.println(“finally”); } } public static void main(String args[]) { try { aMethod(); } catch (Exception e) { System.out.println(“exception”); } System.out.println(“finished”); } } What is the result?()
第10题:
//point X public class foo { public static void main (Stringargs) throws Exception { java.io.printWriter out = new java.io.PrintWriter { new java.io.outputStreamWriter (System.out), true; out.printIn(“Hello”); } } } Which statement at PointX on line 1 allows this code to compile and run?()