public class useCup{???? public static void main(String[] args){???? ???? Cup cup = new Cup();???? ????Cup cup2 = new Cup(2.5f, 2, 1);???? }???? ???? public class Cup {???????? float volume;???????? int shape;???????? int colour;???????? public Cup(){???????? ???? System.out.println("水杯可以用來裝液體");???????? }???????? public Cup(float volume,int shape,int colour){???????????? volume = volume;???????????? if(0<volume||volume<=1.0){???????????? ???? System.out.println("說明此杯為小型水杯！");???????????? }else if(1.0<volume||volume<=3.0){???????????? ???? System.out.println("說明此杯為中型水杯！");???????????? }else if(3.0<volume||volume<=5.0){???????????? ???? System.out.println("說明此杯為大型水杯！");???????????? }else{???????????? ???? System.out.println("輸入體積超出正常數值，請從新輸入！");???????????? }???????????? switch (shape){???????????????? case 1:???????????????? System.out.println("杯型為圓柱型！");???????????????? break;???????????????? case 2:???????????????? System.out.println("杯型為圓臺型！");???????????????? break;???????????????? default:???????????????? System.out.println("輸入錯誤，請從新輸入！");???????????? }???????????? shape = shape;???????????? switch (colour){???????????????? case 1:???????????????? System.out.println("水杯顏色為黃色！");???????????????? break;???????????????? case 2:???????????????? System.out.println("水杯顏色為綠色！");???????????????? break;???????????????? case 3:???????????????? System.out.println("水杯顏色為淡紫色！");???????????????? break;???????????????? default:???????????????? System.out.println("沒有該顏色類型的水杯，請從新選擇顏色！");???????????? }???????? ????colour = colour;???????? ????System.out.println("水杯可以有體積，形狀，顏色進行區(qū)分");???? ????}???? }}問：為什么我的水杯volume 屬性不管賦何值，結果都是“說明此杯為小型水杯！”呢?求大神指教，最好講的詳細些，謝謝！