分析下列程序:public class class4{private string _sData = "";public string sData{set{_sData = value;}}}在Main 函数中,在成功创建该类的对象obj 后,下列哪些语句是合法的?()
A.obj.sData = "It is funny!";
B.Consol
C.WriteLine(obj.sData);
D.obj._sData = 100;
E.obj.set(obj.sData);
A.obj.sData = "It is funny!";
B.Consol
C.WriteLine(obj.sData);
D.obj._sData = 100;
E.obj.set(obj.sData);
A.import jav
B.awt.
C.package mypackage
D.class OtherClass{ }
E.public class MyClass{ }
A.有错误,变量i没有初始化。
B.null
C.1
D.0
程序运行的结果是:_______________。
public class Example{
String str=new String("good");
char[]ch={'a','b','c'};
public static void main(String args[]){
Example ex=new Example();
ex.change(ex.str,ex.ch);
System.out.print(ex.str+" and ");
Sytem.out.print(ex.ch);
}
public void change(String str,char ch[]){
str="test ok";
ch[0]='g';
}
}
分析一下这段程序的输出 (Autodesk)
class B
{
public:
B()
{
cout<<"default constructor"<}
~B()
{
cout<<"destructed"<}
B(int i):data(i) //B(int) works as a converter (int -> instance of B)
{
cout<<"constructed by parameter " << data <}
private:
int data;
};
B Play(B b)
{
return b ;
}
程序阅读:public class test
{
public static void main(String argv[])
{
boolean b1 = true;
if((b1 ==true) || place(true))
{
System.out.println("Hello Crowle");
}
}
public static boolean place(boolean location)
{
if(location==true)
{
System.out.println("Borcetshire");
}
System.out.println("Powick");
return true;
}
}
输出下面程序结果。
#i nclude <iostream.h>
class A
{
public:
virtual void print(void)
{
cout<<"A::print()"<<endl;
}
};
class B:public A
{
public:
virtual void print(void)
{
cout<<"B::print()"<<endl;
};
};
class C:public B
{
public:
virtual void print(void)
{
cout<<"C::print()"<<endl;
}
};
void print(A a)
{
a.print();
}
void main(void)
{
A a, *pa,*pb,*pc;
B b;
C c;
pa=&a;
pb=&b;
pc=&c;
a.print();
b.print();
c.print();
pa->print();
pb->print();
pc->print();
print(a);
print(b);
print(c);
}
A:
A::print()
B::print()
C::print()
A::print()
B::print()
C::print()
A::print()
A::print()
A::print()
阅读下列程序,请写出程序的运行结果。
import java.applet.*;
import java.awt.*;
public class C extends Applet implements Runnable
{
Thread redBall,blueBall;
Graphics redPen,bluePen;
int blueSeta=0,redSeta=0;
public void init()
{
setSize(250,200);
redBall=new Thread(this);
blueBall=new Thread(this);
redPen=getGraphics();
bluePen=getGraphics();
redPen.setColor(Color.red);
bluePen.setColor(Color.blue);
setBackground(Color.gray);
}
public void start()
{
redBall.start();
blueBall.start();
}
public void run()
{
intx,y;
while(true)
{
if(Thread.currentThread()==redBall)
{//以下代码为顺时针画圆
x=(int)(80.0*Math.cos(3.1415926/180.0*redSeta));
y=(int)(80.0*Math.sin(3.1415926/180.0*redSeta));
redPen.setColor(Color.gray);
redPen.fillOval(100+x,100+y,10,10);
redSeta+=3;
if(redSeta>=360)redSeta=0;
x=(int)(80.0*Math.cos(3.1415926/180.0*redSeta));
y=(int)(80.0*Math.sin(3.1415926/180.0*redSeta));
redPen.setColor(Color.red);
redPen.fillOval(100+x,100+y,10,10);
try{redBall.sleep(20);}
catch(InterruptedException e){}
}
elseif(Thread.currentThread()==blueBall)
{//以下代码为顺时针画圆
x=(int)(80.0*Math.cos(3.1415926/180.0*blueSeta));
y=(int)(80.0*Math.sin(3.1415926/180.0*blueSeta));
bluePen.setColor(Color.gray);
bluePen.fillOval(150+x,100+y,10,10);
blueSeta-=3;
if(blueSeta<=-360)blueSeta=0;
x=(int)(80.0*Math.cos(3.1415926/180.0*blueSeta));
y=(int)(80.0*Math.sin(3.1415926/180.0*blueSeta));
bluePen.setColor(Color.blue);
bluePen.fillOval(150+x,100+y,10;10);
try{blueBall.sleepp(40);}
catch(InterruptedException e){}
}
}
}
}
分析一下这段程序的输出(Autodesk)
class B
{
public:
B()
{
cout<<"default constructor"<<endl;
}
~B()
{
cout<<"destructed"<<endl;
}
B(int i):data(i) //B(int) works as a converter (int ->
instance of B)
{
cout<<"constructed by parameter " << data <<endl;
}
private:
int data;
};
B Play(B b)
{
return b ;
}
阅读下面程序,写出输出结果。
#include using namespace std ; class A { int a, b; public : A() { a = b = 0; }
A(int aa, int bb) { a = aa; b = bb; cout << a << ' ' << b << endl ; } }; int main() { A x, y(2,3);
return 0; }
class A
{
int a;
A(int b)
{a=b;}
void show()
{System.out.println(“a=”+a);}
}
public class Class1
{
public static void main (String args[])
{
A bj=new A(12345);
boolean b=false;
char ch=97;
obj.show();
System.out.println(“b=”+b+”/tch=”+ch);
}
}