public class Threads 1 { intx=0; public class Runner implements Runnable { public void run() { int current = 0; for(int=i=0;i<4;i++){ current = x; System.out.print(current + “, “); x = current + 2; } } } public static void main(String[] args) { new Threads1().go(); } public void go() { Runnable r1 = new Runner(); new Thread(r1).start(); new Thread(r1 ).start(); } } Which two are possible results?()
第1题:
下面程序创建了一个线程并运行,请填空,使程序完整。
public class ThreadTest {
public static void main (String[] args) {
Hello h=Hew Hello ();
【 】
t.start ();
}
}
class Hello implements Runnable {
int i;
public void run () {
while(true) {
System.out.println("Hello" +i++);
if(i==5) break;
}
}
}
第2题:
下面程序的输出结果是什么? class C1{ static int j=0; public void method(int a){ j++; } } class Test extends C1{ public int method(){ return j++; } public void result(){ method(j); System.out.println(j+method()); } public static void main(String args[]){ new Te
A.0
B.1
C.2
D.3
第3题:
下面程序的输出结果是( )。 public class Sun { public static void main(String args[ ]) { int x=0; for(int i=1;i<=4;i++) { x=4; for(int j=1;j<=3;j++) { x=3; for(int k=1;k<=2;k++) { x-x+6; } } } System.out.println(x); } }
A.7
B.15
C.157
D.538
第4题:
下面代码的运行结果是 public class Test{ public static void main(String args[]){ for(int i=0; i<3;i++){ if(i<2) continue; System.out.println(i); } } }
A.0
B.1
C.2
D.3
第5题:
下列程序执行后的结果为______。 public class exl2 { public static void main(string[] args) { int n=4; int x=0; do{ System.out.print(n); }while (x++<n--); } }
A.12
B.432
C.43
D.4
第6题:
本题中,鼠标在窗口中单击一下,就在单击的位置生成一个小矩形,如果在小矩形上双击鼠标左键,则删除小矩形。 import java.awt.*; import java.awt.event.*; import javax swing.*; class MousePanel extends JPanel extends MouseMo- tionListener {public MousePanel {addMouseListener(new MouseAdapter {public void mousePressed(MouseEvent evt) {int X=evt.getX; int Y=evt.getY; current=find(x,y); if(current<0) add(x,y); } public void mouseClicked(MouseEvent evt) {int X=evt.getX; int Y=evt.getY; if(evt.getClickCount>=2) {remove(current); } } }); addMouseMotionListener(this); } public void paintComponent(Graphics g) {super.paintComponent; for(int i=0;i<nsquares;i++) draw(g,i); } public int find(int X,int y) (for(int i=0;i<nsquares;i++) if(squares[i].x-SQUARELENGTH/2<= x X<=squares[i].x+SQuARELENGTH/2 squares[i].Y-SQUARELENGTH/2< =Y y<=squares[i].Y+SQUARELENGTH /2) return i ; return-1 ; } public void draw(Graphics g,int i) {g.drawRect(squares[i].X-SQUARE- LENGTH/2。 squares[i].Y-SQUARELENGTH/2, SQUARELENGTH, SQUARELENGTH); } public void add(int X,int Y) {if(nsquares<MAXNSQUARES) {squares[nsquares]=new Point(x,y); current=nsquares ; nsquares++; repaint; } } public void remove(int n) {if(n<0 ‖ n>=nsquares)return; Nsquares- -; squares[n]=squares[nsquares]; if(current= =n)current= -l; repaint; } public void mouseMoved(MouseEvent evt) {} public void mouseDragged(MouseEvent evt) {} private static final int SQUARELENGTH=10: private static final int MAXNSQUARES=100; private Point[]squares=new Point[MAX- NSQUARES]; private int nsquares=0; private int current=-l; } class MouseFrame. extends JFramc {public MouseFrame {setTitle("java3"); setSize(300,200); addWindowListener(new WindowAdapter {public void windowClosing(WindowEvent e) {System.exit(0); } }); Container contentPane=getContentPane; contentPane.add(MousePanel); } } public class java3 {public static void main(String[]args) {JFrame. frame=new MouseFrame; frame.show; } }
第7题:
下列代码的执行结果是public class Test{ public int aMethod(){ static int i=0; i++; System.out.println(i); } public static void main(String args[]){ Test test= new Test(); test. aMethod(); }}
A.编译错误
B.0
C.1
D.运行成功,但不输出
第8题:
下列程序打包到example包,main方法调用线程类输出0~9这10个数,请填写横线处的内容。
注意:请勿改动main()主方法和其他已有语句内容,仅在横线处填入适当语句。
______
interface MyInterface
{
public abstract void print(int n);
}
class Mythread extends Thread ______ MyInterface
{
public void run()
{
for(int i = 0; i < 10; i++)
this.print(i);
}
public void print(int n)
{
System.out.print(n +" ");
}
}
public class Example1_6
{
public static void main(String argv[])
{
Mythread th = new Mythread();
______
}
}
第9题:
下列程序执行之后,输出的结果是______。 public class ex4 { public static void main(String[] args) { int j=0; for(int i=3;i>0;i--) { j+=i; int x=2; while(x<j) { x+=1; System.out,print(x); } } } }
A.3555
B.35556666
C.33453456
D.345
第10题:
在下面程序的下画线处应填入的选项是 public class Test______{ public static void main(String args[]) { Test t=new Test(); Thread tt=new Thread(t); tt.start(); } public void run() { for(int i=0;i<5;i++) System.out.println("i="+i); } }
A.implements Runnable
B.extends Thread
C.implements Thread
D.extends Runnable