使用此关键字调用另一个构造函数

class Circle { 
/** 
来 自 
nowjava
**/

        int x, y, radius; 


        Circle (int xPoint, int yPoint, int radiusLength) { 

            this.x = xPoint; 

            this.y = yPoint; 

            this.radius = radiusLength; 

        } 


        Circle (int xPoint, int yPoint) { 

            this(xPoint, yPoint, 1); 

        } 

    }