Java實作復數Complex的加減乘除運算、取模、求幅角角度

/**
 * @Author: Yeman
 * @Date: 2021-09-23-9:03
 * @Description:
 */

class Complex{
    private double realPart;  //復數的實部
    private double imaginaryPart;  //復數的虛部

    public Complex() { //空參構造器
    }

    public Complex(double realPart, double imaginaryPart) {
        this.realPart = realPart;
        this.imaginaryPart = imaginaryPart;
    }

    //屬性的get、set方法
    public double getRealPart() {
        return realPart;
    }

    public void setRealPart(double realPart) {
        this.realPart = realPart;
    }

    public double getImaginaryPart() {
        return imaginaryPart;
    }

    public void setImaginaryPart(double imaginaryPart) {
        this.imaginaryPart = imaginaryPart;
    }

    //加法運算
    public Complex add(Complex otherComplex){
        if (otherComplex != null) {
            return new Complex(this.getRealPart() + otherComplex.getRealPart(),this.getImaginaryPart() + otherComplex.getImaginaryPart());
        }else throw new RuntimeException("參與運算的物件為空！");
    }

    //減法運算
    public Complex decrease(Complex otherComplex){
        if (otherComplex != null) {
            return new Complex(this.getRealPart() - otherComplex.getRealPart(),this.getImaginaryPart() - otherComplex.getImaginaryPart());
        }else throw new RuntimeException("參與運算的物件為空！");
    }

    //乘法運算
    public Complex multiply(Complex otherComplex){
        if (otherComplex != null) {
            double newReal = this.getRealPart() * otherComplex.getRealPart() - this.getImaginaryPart() * otherComplex.getImaginaryPart();
            double newImaginary = this.getImaginaryPart() * otherComplex.getRealPart() + this.getRealPart() * otherComplex.getImaginaryPart();
            return new Complex(newReal,newImaginary);
        }else throw new RuntimeException("參與運算的物件為空！");
    }

    //除法運算
    public Complex divide(Complex otherComplex){
        if (otherComplex != null) {
            if (otherComplex.getRealPart() != 0 && otherComplex.getImaginaryPart() != 0){
                double newReal = (this.getRealPart() * otherComplex.getRealPart() + this.getImaginaryPart() * otherComplex.getImaginaryPart()) / (otherComplex.getRealPart() * otherComplex.getRealPart() + otherComplex.getImaginaryPart() * otherComplex.getImaginaryPart());
                double newImaginary = (this.getImaginaryPart() * otherComplex.getRealPart() - this.getRealPart() * otherComplex.getImaginaryPart()) / (otherComplex.getRealPart() * otherComplex.getRealPart() + otherComplex.getImaginaryPart() * otherComplex.getImaginaryPart());
                return new Complex(newReal,newImaginary);
            }else throw new RuntimeException("除數不能為0！");
        }else throw new RuntimeException("參與運算的物件為空！");
    }

    //取模
    public double delivery(){
            return Math.sqrt(this.getRealPart() * this.getRealPart() + this.getImaginaryPart() * this.getImaginaryPart());
    }

    //幅度值（角度）
    public double angle(){
        double atan;
        if (this.getRealPart() != 0) { //注意，該處double型變數若有進行其他操作，則不能以此方式判斷其等于0，應該是其絕對值小于某個很小的數；而這當前情景下，其實精度問題并不影響，因此可以這樣寫
            atan = Math.atan(this.getImaginaryPart() / this.getRealPart());
        }else {
            if (this.getImaginaryPart() > 0) {
                atan = Math.PI / 2;
            }else if (this.getImaginaryPart() < 0){
                atan = -Math.PI / 2;
            }else atan = Math.atan(0);
        }
        return atan;
    }

}

//測驗主類
public class ComplexTest {
    public static void main(String[] args) {
        Complex complex1 = new Complex(0, 5);
        Complex complex2 = new Complex(3, -3);

        //取模測驗
        double delivery = complex1.delivery();
        System.out.println("(" + complex1.getRealPart() + "+" + complex1.getImaginaryPart() + "i" + ")" + "的模為：" + delivery);

        //求角度測驗
        double angle = complex1.angle();
        System.out.println("(" + complex1.getRealPart() + "+" + complex1.getImaginaryPart() + "i" + ")" + "的角度為：" + Math.toDegrees(angle) + "°");

        //加運算
        Complex add = complex1.add(complex2);
        System.out.println("(" + complex1.getRealPart() + "+" + complex1.getImaginaryPart() + "i" + ")" + "+" + "(" + complex2.getRealPart() + complex2.getImaginaryPart() + "i" + ")" + "=" + "(" + add.getRealPart() + "+" + add.getImaginaryPart() + "i" + ")");

        //減運算
        Complex decrease = complex1.decrease(complex2);
        System.out.println("(" + complex1.getRealPart() + "+" + complex1.getImaginaryPart() + "i" + ")" + "-" + "(" + complex2.getRealPart() + complex2.getImaginaryPart() + "i" + ")" + "=" + "(" + decrease.getRealPart() + "+" + decrease.getImaginaryPart() + "i" + ")");

        //乘法運算
        Complex multiply = complex1.multiply(complex2);
        System.out.println("(" + complex1.getRealPart() + "+" + complex1.getImaginaryPart() + "i" + ")" + "x" + "(" + complex2.getRealPart() + complex2.getImaginaryPart() + "i" + ")" + "=" + "(" + multiply.getRealPart() + "+" + multiply.getImaginaryPart() + "i" + ")");

        //除法運算
        Complex divide = complex1.divide(complex2);
        System.out.println("(" + complex1.getRealPart() + "+" + complex1.getImaginaryPart() + "i" + ")" + "/" + "(" + complex2.getRealPart() + complex2.getImaginaryPart() + "i" + ")" + "=" + "(" + divide.getRealPart() + "+" + divide.getImaginaryPart() + "i" + ")");
    }
}