Question

JAVA编程创建一个Point类

编程创建一个Point类，在其中定义两个变量表示一个点的坐标值，再定义构造函数初始化为坐标原点，然后定义一个方法实现点的移动，再定义一个方法打印当前点的坐标。并创建一个对象验证。
提示：关键代码如下：
void move(int newX,int newY){
x=newX;
y=newY;
}
void print(){
System.out.println(name+":x="+x+" y="+y);
}
…
p.print();
p.move(50,50);
System.out.println("**after moving**");
p.print(); //call method of an object

Answer 1

public class Point
{
private int x;
private int y;
private String name;
public Point()
{
this.x = 0;
this.y = 0;
this.name = "default";
}

public Point(int x,int y,String name)
{
this.x = x;
this.y = y;
this.name = name;
}

public void move(int newX,int newY)
{
x = newX;
y = newY;
}

public void print()
{
System.out.println(name+":x="+x+" y="+y);
}

public static void main (String[] args)
{
Point p1 = new Point();
p1.print();
p1.move(50,50);
System.out.println("**after moving**");
p1.print();

Point p2 = new Point(10,10,"Point2");
p2.print();
p2.move(150,150);
System.out.println("**after moving**");
p2.print();
}
}

Answer 2

public
class
Test102
{
public
static
void
main(String[]
args)
{
Point
point
=
new
Point();
point.printPoint();
point.moveTo(1,
3);
System.out.println("--移动后--");
point.printPoint();
}
}
class
Point
{
private
float
x;
private
float
y;
public
Point()
{
this.x
=
0;
this.y
=
0;
}
/**
*
移动到点(dest1,dest2)
*
@param
dest1
*
@param
dest2
*/
public
void
moveTo(float
dest1,
float
dest2)
{
this.x
=
dest1;
this.y
=
dest2;
}
public
void
printPoint()
{
System.out.print("当前点坐标:"
+
"("
+
x
+
","
+
y
+
")\n");
}
}