java第四次作业
1.编写“电费管理类”及其测试类。
package LHB.inherit; public class Electricityfees { private int lastmonth,thismonth;/*上月电表读数,本月电表读数*/ public Electricityfees() { } public Electricityfees(int lastmonth,int thismonth) { this.lastmonth=lastmonth; this.thismonth=thismonth; } public int getLastmonth() { return lastmonth; } public void setLastmonth(int lastmonth) { this.lastmonth = lastmonth; } public int getThismonth() { return thismonth; } public void setThismonth(int thismonth) { this.thismonth = thismonth; } public void print() { System.out.print("上月电表读数为:"+lastmonth+" "); System.out.println("这个月电表读数为:"+thismonth+" "); } }
2. 编写“圆柱体”类及其测试类。
package LHB.inherit; public class Cylinder { private int r,high; /*半径,高*/ public Cylinder(int r,int high) { this.r=r; this.high=high; } public double area() { double s; s=3.14*r*r; return s; } public double volume() { double v; v=area()*high; return v; } public void print() { System.out.println("圆的半径是:"+r+" "+"高是:"+high); System.out.printf("圆的底面积是:%.2f 体积是:%.2f\n",area(),volume()); } public int getR() { return r; } public void setR(int r) { this.r = r; } public int getHigh() { return high; } public void setHigh(int high) { this.high = high; } public static void main(String[] args) { } }
3.编写“四则运算类”及其测试类。
package LHB.inherit; public class Elementary { private int num1,num2; private char Char; public Elementary(int num1,int num2) { this.num1=num1; this.num2=num2; } public Elementary(int num1,int num2,char Char) { this.num1=num1; this.num2=num2; this.Char=Char; System.out.print("操作结果是:"); switch(Char) { case'+': System.out.println(add());break; case'-': System.out.println(minus());break; case'*': System.out.println(multiply());break; case'/': System.out.println(divide());break; } } public int add() { int sum; sum=num1+num2; return sum; } public int minus() { int minu; minu=num1-num2; return minu; } public int multiply() { int mult; mult=num1*num2; return mult; } public int divide() { int divid; divid=num1/num2; return divid; } public int getNum1() { return num1; } public void setNum1(int num1) { this.num1 = num1; } public int getNum2() { return num2; } public void setNum2(int num2) { this.num2 = num2; } public char getChar() { return Char; } public void setChar(char c) { Char = c; } }