子类能不能继承父类的构造方法?
程序代码:
interface A { float perimeter(); float square(); } class Rectangle implements A { float a, b; public Rectangle(float a) { this.a = a; this.b = a; } public Rectangle(float a, float b) { this.a = a; this.b = b; } @Override public float perimeter() { return 0; } @Override public float square() { return 0; } } class Square extends Rectangle { // public Square(float a) // { // this.a = a; // this.b = a; // } public float perimeter() { float l = (a+b)*2; return l; } public float square() { float s = a * b; return s; } } class M { public static void main(String[] args) { Square sq = new Square(5); System.out.println("正方形的周长:"+sq.perimeter()+" "+"正方形的面积为:"+sq.square()); } }