A.public int compute(int x,int y){}B.public double compute(double x){}C.public double compute(double x,double y){}D.public double compute(double x,double y,double z){}
A.this.xB.x =10C.return xD.子类继承x
A.pakcage c;B.package b.c.a;C.package c.b.a;D.package a.b.c;