内容发布更新时间 : 2024/12/26 4:16:30星期一 下面是文章的全部内容请认真阅读。
super(); x=8;
System.out.println(\+x); }
void doPrint(){ super.doPoint();
System.out.println(\+super.x+\+x); } }
in subClass():x=8 super.x=3 sub.x=8
4、在右边的矩形框中写出该程序运行的结果。
class StaticTest {
static int x=1; int y;
StaticTest() { y++; }
public static void main(String args[ ]){ StaticTest st=new StaticTest(); System.out.println(\
System.out.println(\ st=new StaticTest();
System.out.println(\} static { x++;} }
5、写出下列程序的运行结果
class Time1{
private int hour; private int minute; private int second; public Time1(){ setTime(0,0,0); }
public Time1(int hh){ setTime(hh,0,0); }
public Time1(int hh,int mm){ setTime(hh,mm,0); }
public Time1(int hh,int mm,int ss){ setTime(hh,mm,ss); }
public String toString(){
retunr (hour+\ } }
public class MyTime1{
private static Time1 t0,t1,t2,t3;
public static void main(String[] args){ t0=new Time1(); t1=new Time1(11); t2=new Time1(22,22); t3=new Time1(33,33,33);
System.out.println(\ System.out.println(\ System.out.println(\ System.out.println(\ }
}
答案:t0=0:00:00 t1=11:00:00 t2=22:22:00 t3=0:33:33
6、在右边的矩形框中写出该程序运行的结果。
public class TestArray
{ public static void main(String args[ ]){ int i , j ;
int a[ ] = {1,3,2,5,4};
for ( i = 0 ; i < a.length-1; i ++ ) { int k = i;
for ( j = i ; j < a.length ; j++ ) if ( a[j]>a[k] ) k = j; int temp =a[i]; a[i] = a[k];
a[k] = temp; }
for ( i =0 ; i 答案:5、4、3、2、1 7、写出下列程序的运行结果 public class Exam { public static void main(String[] args) { int x=5; int m=0; x+=x++ +(x++ +m); System.out.println(x); } } 答案:16 8、在右边的矩形框中写出该程序运行的结果。 class MyException extends Exception{ 答案: private int detail; MyException( int a ){ detail = a;} public String toString( ){ return \} public class ExceptionDemo{ public static void compute(int a) throws MyException { System.out.println(\ if( a>10 ) throw new MyException(a); System.out.println(\} public static void main( String args[] ){ try{ compute(6 ); compute( 12 ); } catch( MyException e ){ System.out.println(\} } normal exit called compute(12) Caught MyException 12 9、试标识出下面的QQ类中的所有无效语句(用下划线标示出),对每个无效语句说出其无效的理由。 class QQ{ private int alpha; private int beta; public static void classMethod(){ this.beta=this.alpha*2; //beta和alpha不是静态. } public QQ(){ //无返回值,应该用void QQ(0,0); } public QQ(int x,int y){ //无返回值,应该用void alpha=this.x; //应该是this.alpha=x;this.beta=y; beta=this.y; } } 10、在右边的矩形框中写出该程序运行的结果。 class OverloadDemo{ void testOverload( int i ){ System.out.println(“int”); } void testOverload(String s){ System.out.println(“String”); } public static void main(String args[ ]){ OverloadDemo a=new OverloadDemo ( ); char ch=’x’; a.testOverload(ch); } } 答案:int 11、写出下列程序的运行结果 public class Text { } public int t=4; public static void main(String[] args) { } public void NumberPlay(){ } int t=2; t=t+5; this.t=this.t-2; t=t-this.t; System.out.print(t+\); System.out.println(this.t); new Text().NumberPlay(); 答案:5 2 12、在右边的矩形框中写出该程序运行的结果。 class First{ public First(){ aMethod(); } public void aMethod(){ System.out.println(“in First class”);} } public class Second extends First{ public void aMethod(){ System.out.println(“in Second class”);} public static void main(String[ ] args){ new Second( ); } } 答案:in Second class 13、设计实现地址概念的类Address。Address具有属性:省、市、街道、门牌号、邮编,具有能设置和获取属性的方法。 14、请将下列程序补充完整 下列程序定义一个表示圆形的类,能够计算园面积和周长 class MyCircle{ float r; final double PI=3.14159; public double area(){ //计算面积 return PI*r*r; } public void setR(float x){ //设置半径 r=x; }