java简单的复数类 用java实现复数的加减乘除

1、一个复数类Complex由两部分组成：实部real和虚部imaginary，两个复数可以进行加减乘除四则运算。
　　试设计这个复数类，然后在另一个类的程序入口演示。

 

public class Test {
	public static void main(String[] args) {
//	定义两个对象并赋值：c1(a+bi)=(2+4i),c2=(c+di)=(6+16i)
		Complex c1=new Complex();
		c1.real=2;
		c1.imaginary=4;
		Complex c2=new Complex();
		c2.real=6;
		c2.imaginary=16;

//		以字符串的方式输出：采用标准格式输出，即a+bi
		System.out.println("两个复数相加得："+c1.add(c2));

//		在每次调用并运算（此时real值发生变化）之后，再重新赋值：
		c1.real=2;
		c1.imaginary=4;		System.out.println("两个复数相减得："+c1.sub(c2));
		c1.real=2;
		c1.imaginary=4;

		System.out.println("两个复数相乘得："+c1.mul(c2));
		c1.real=2;
		c1.imaginary=4;

		System.out.println("两个复数相除得："+c1.div(c2));
	}
}
class Complex
{
	double real;
	double imaginary;
//最后以字符串输出的格式：
//1.虚部为正值时，实部+"+"+虚部+"i"	2.虚部为0时，只有实部，即实部+""	3.虚部为负值时，实部+""+虚部+"i"

//	加法，减法：直接实部加减实部，虚部加减虚部
	String add(Complex c)
	{
		if(imaginary+c.imaginary>0)
			return (real=real+c.real)+"+"+(imaginary=imaginary+c.imaginary)+"i";
		else if(imaginary+c.imaginary==0)
			return (real=real+c.real)+"";
		else
			return (real=real+c.real)+""+(imaginary=imaginary+c.imaginary)+"i";
	}
	String sub(Complex c)
	{
		if(imaginary-c.imaginary>0)
			return (real=real-c.real)+"+"+(imaginary=imaginary-c.imaginary)+"i";
		else if(imaginary-c.imaginary==0)
			return (real=real-c.real)+"";
		else
			return (real=real-c.real)+""+(imaginary=imaginary-c.imaginary)+"i";
	}
//	乘法的公式：(a+bi)*(c+di) = a*c + bi*c + a*di + bi*di = a*c + (b*d)(i^2) + (b*c+a*d)i 

//				注：此处的i^2直接赋值-1，即 return a*c-b*d+(b*c+a*d)i
	String mul(Complex c)
	{
		if(imaginary*c.real+real*c.imaginary>0)
			return (real*c.real)-(imaginary*c.imaginary)+"+"+(imaginary*c.real+real*c.imaginary)+"i";
		else if(imaginary*c.real+real*c.imaginary==0)
			return (real*c.real)-(imaginary*c.imaginary)+"";
		else
			return (real*c.real)-(imaginary*c.imaginary)+""+(imaginary*c.real+real*c.imaginary)+"i";
	}
//	除法的公式：(a+bi)/(c+di) = (a+bi)*(c-di) / c^2+d^2

//				注：在乘法的基础上得到格式A+Bdi，再进行A /c^2+d^2，B /c^2+d^2 + "i"
	String div(Complex c)
	{
		if(imaginary*c.real-real*c.imaginary>0)
			return ((real*c.real)+(imaginary*c.imaginary))/(c.real*c.real+c.imaginary*c.imaginary)+"+"+(imaginary*c.real-real*c.imaginary)/(c.real*c.real+c.imaginary*c.imaginary)+"i";
		else if(imaginary*c.real-real*c.imaginary==0)
			return ((real*c.real)+(imaginary*c.imaginary))/(c.real*c.real+c.imaginary*c.imaginary)+"";
		else
			return ((real*c.real)+(imaginary*c.imaginary))/(c.real*c.real+c.imaginary*c.imaginary)+""+(imaginary*c.real-real*c.imaginary)/(c.real*c.real+c.imaginary*c.imaginary)+"i";

	}
}
/*Complex c1=new Complex();
		c1.real=2;
		c1.imaginary=4;

		Complex c2=new Complex();
		c2.real=6;
		c2.imaginary=16;

即：c1=2+4i
c2=6+16i
数学运算结果：

两者相加：8+20i
两者相减：-4-12i

两者相乘：-52+56i
(2+4i)*(6+16i)

两者相除：0.2602739726027397-0.0273972602739726i
(2+4i)/(6+16i)=(2+4i)*(6-16i)/(6*6+16*16)*/

weiyulan-1998