Java类关于构造方法

1.默认构造方法的类
package min;

public class Lainxi {
private int x;//private表示私有成员，修饰的类属性只能在同一个类中定义的方法使用
private int y;
public int getX(){return x;};
public int getY(){return y;};
public void setX(int newX){x=newX;};
public void setY(int newY){y=newY;};
double distance(){return Math.sqrt(xx+yy);}
public static void main(String[]args){
Lainxi L1=new Lainxi();
System.out.println(L1.x+","+L1.y+“distance:”+L1.distance());
}

}

2.用类的方法求解程序ax*x+bx+c=0

package min;

public class Lainxi {
private double a,b,c;
public Lainxi(double newA,double newB,double newC)
{
a=newA;
b=newB;
c=newC;
}
private double b24ac()
{
return bb-4ac;
}
private double x1,x2,rb24ac;
public double getX1(){return x1;}
public double getX2(){return x2;}
public void x1x2()
{
rb24ac=b24ac();
if(rb24ac==0)
{x1=-b/(2a);
x2=x1;
System.out.println(“x1.x2的值如下：”+x1+"."+x2);
}
if(rb24ac==0){
x1=(-b-Math.sqrt(rb24ac))/(2a);
x2=(-b+Math.sqrt(rb24ac))/(2a);
System.out.println(“x1.x2的值如下：”+x1+"."+x2);
}
else
{
System.out.println(“x1.x2无解”);
}
}
public static void mian(String args[])
{
Lainxi l=new Lainxi(1,2,1);
l.x1x2();

}

}