用java实现复数的加减乘除运算(改进第1次)

1.背景

前两天为了赶速度，自己很快实现了如题java老师布置的作业，并在csdn上写了博客，记录学习过程，原博客链接为:http://blog.csdn.net/u010043538/article/details/12765527。但是很快有无私的网友指出了其中一个显然的错误：没有考虑除数为0的情况。虽然java初学，不过错就是错，没有啥理由。自己以后写老师作业，会尽可能深进去，把已经自学过的内容体现出来，而不是跟老师上课的内容来写代码。在此基础上，尽可能保证快速解决问题。

此次改进修正了错误：没有考虑除数为0的情况。并对程序的封装性做了一定程度的改进。

2.具体代码(附注释)

package Four;

/**

* @author Kun Sun

* @Date： 2013.10.17

*/

public class Complex { // 复数类

double real; // 实部

double image; // 虚部

Complex(double real,double image){ // 带参数的构造方法

this.real = real;

this.image = image;

}

public Complex() {

// TODO Auto-generated constructor stub

}

public double getReal() {

return real;

}

public void setReal(double real) {

this.real = real;

}

public double getImage() {

return image;

}

public void setImage(double image) {

this.image = image;

}

Complex add(Complex a){ // 复数相加

double real2 = a.getReal();

double image2 = a.getImage();

double newReal = real + real2;

double newImage = image + image2;

Complex result = new Complex(newReal,newImage);

return result;

}

Complex sub(Complex a){ // 复数相减

double real2 = a.getReal();

double image2 = a.getImage();

double newReal = real - real2;

double newImage = image - image2;

Complex result = new Complex(newReal,newImage);

return result;

}

Complex mul(Complex a){ // 复数相乘

double real2 = a.getReal();

double image2 = a.getImage();

double newReal = real*real2 - image*image2;

double newImage = image*real2 + real*image2;

Complex result = new Complex(newReal,newImage);

return result;

}

Complex div(Complex a){ // 复数相除

double real2 = a.getReal();

double image2 = a.getImage();

double newReal = (real*real2 + image*image2)/(real2*real2 + image2*image2);

double newImage = (image*real2 - real*image2)/(real2*real2 + image2*image2);

Complex result = new Complex(newReal,newImage);

return result;

}

public void print(){ // 用于格式化输出

if(image > 0){

System.out.println(real + " + " + image + "i");

}else if(image < 0){

System.out.println(real + "" + image + "i");

}else{

System.out.println(real);

}

}

// 封装了具体运算，主要为对输入进行转换，对输出封装

public static void talk(String data1_1,String data1_2,String data2_1,String data2_2,String operation){

// 以下语句为格式转换

double dat1_1 = Double.parseDouble(data1_1); // 把string型实部转为double型

double dat1_2 = Double.parseDouble(data1_2.substring(0,data1_2.length()-1));// 把去除"i"的string型虚部转为double型

double dat2_1 = Double.parseDouble(data2_1);// 把string型实部转为double型

double dat2_2 = Double.parseDouble(data2_2.substring(0,data2_2.length()-1));// 把去除"i"的string型虚部转为double型

Complex num1 = new Complex(dat1_1,dat1_2);

Complex num2 = new Complex(dat2_1,dat2_2);

Complex result;

int a,b;

if(operation.equals("+")){ // 两数相加

result = num1.add(num2);

result.print();

}

if(operation.equals("-")){ // 两数相减

result = num1.sub(num2);

result.print();

}

if(operation.equals("*")){ // 两数相乘

result = num1.mul(num2);

result.print();

}

if(operation.equals("/")){ // 两数相除

if(num2.real * num2.real + num2.image*num2.image != 0){

result = num1.div(num2);

result.print();

}else{

System.out.println("运算出错,除数运算中除数不能为0,请用户重新输入!");

}

}

}

}

package Four;

import java.util.Scanner;

/**

* @author Kun Sun

* @Date： 2013.10.17

*/

public class MainClass { // 用于测试复数类

/**

* @param args

*/

public static void main(String[] args) {

// TODO Auto-generated method stub

Complex complex = new Complex();

// 以下测试中的talk()中的解释为

// talk(string data1_1,string data1_2,string data2_1,string data2_2,string operation);

// data1_1,data1_2依次为第一个复数的实部和虚部

// data2_1,data2_2依次为第二个复数的实部和虚部

// operation为两个复数运算的操作符,每种测试都做加减乘除

System.out.println("测试1:-------------------------"); // 一般测试

complex.talk("5", "4i", "3", "6i", "+");

complex.talk("5", "4i", "3", "6i", "-");

complex.talk("5", "4i", "3", "6i", "*");

complex.talk("5", "4i", "3", "6i", "/");

System.out.println("\n测试2:-------------------------"); // 包含负数测试

complex.talk("-2","4i", "5", "-8i","+");

complex.talk("-2","4i", "5", "-8i","-");

complex.talk("-2","4i", "5", "-8i","*");

complex.talk("-2","4i", "5", "-8i","/");

System.out.println("\n测试3:-------------------------"); // 包含小数测试

complex.talk("-1.2","3.1i","4.3","-6.5i","+");

complex.talk("-1.2","3.1i","4.3","-6.5i","-");

complex.talk("-1.2","3.1i","4.3","-6.5i","*");

complex.talk("-1.2","3.1i","4.3","-6.5i","/");

System.out.println("\n测试4:-------------------------"); // 包含除数为0测试

complex.talk("5", "4i", "0", "0i", "+");

complex.talk("5", "4i", "0", "0i", "-");

complex.talk("5", "4i", "0", "0i", "*");

complex.talk("5", "4i", "0", "0i", "/");

}

}

3.测试结果截图