java自定义类本身在println怎么输出

Question

#不知道怎么输出类
#【输入示例】
2 3.08 -2.04 5.06
【输出示例】
(2.0+3.1i) + (-2.0+5.1i) = 8.1i
(2.0+3.1i) - (-2.0+5.1i) = 4.0-2.0i
(2.0+3.1i) * (-2.0+5.1i) = -19.7+3.8i
(2.0+3.1i) / (-2.0+5.1i) = 0.4-0.6i

import java.util.Scanner;
public class Main {
    public static void main(String[] args) {
    Scanner in = new Scanner(System.in);
    double a1 = in.nextDouble();
    double b1 = in.nextDouble();
    double a2 = in.nextDouble();
    double b2 = in.nextDouble();
    Complex a = new Complex(a1, b1);
    Complex b = new Complex(a2, b2);
    Complex c = new Complex();
    System.out.print(a + " + " + b + " = ");
    c = a.add(b);
    c.print();
    System.out.print(a + " - " + b + " = ");
    c = a.sub(b);
    c.print();
    System.out.print(a + " * " + b + " = ");
    c = a.mul(b);
    c.print();
    System.out.print(a + " / " + b + " = ");
    c = a.div(b);
    c.print();
    in.close();
    }    
}

```java
class Complex {
    private double a,b;
    public Complex() {
        a=0;
        b=0;
    }
    public Complex(double q,double p) {
        a=q;
        b=p;
    }
    public double geta() {
        return a;
    }
    public double getb() {
        return b;
    }
    public void print() {
        if(a>0) {
            if(b>0) {
                System.out.printf("%.1f%.1fi/n",Math.abs(a),Math.abs(b));
            }
            else if(b==0) {
                System.out.printf("%.1f/n",Math.abs(a));
            }
            else {
                System.out.printf("%.1f-%.1fi/n",Math.abs(a),Math.abs(b));
            }
            
        }
        else if(a==0) {
            if(b>0) {
                System.out.printf("%.1fi/n",Math.abs(b));
            }
            else if(b==0) {
                System.out.printf("0.0/n");
            }
            else {
                System.out.printf("-%.1fi/n",Math.abs(b));
            }
        }
        else {
            if(b>0) {
                System.out.printf("-%.1f%.1fi/n",Math.abs(a),Math.abs(b));
            }
            else if(b==0) {
                System.out.printf("-%.1f/n",Math.abs(a));
            }
            else {
                System.out.printf("-%.1f-%.1fi/n",Math.abs(a),Math.abs(b));
            }
        }
        
    }
    public Complex add (Complex c) {
        Complex d=new Complex(a+c.geta(),b+c.getb());
        return d;
    }
    public Complex sub (Complex c) {
        Complex d=new Complex(a-c.geta(),b-c.getb());
        return d;
    }
    public Complex mul (Complex c) {
        Complex d=new Complex(a*c.geta()-(b*c.getb()),a*c.getb()+(b*c.geta()));
        return d;
    }
    public Complex div (Complex c) {
        Complex d=new Complex((a*c.geta()+(b*c.getb()))/(c.geta()*c.geta()+c.getb()*c.getb()),(a*c.getb()-(b*c.geta()))/(c.geta()*c.geta()+c.getb()*c.getb()));
        return d;
    }

}

```

Answer 1

可以重写 toString方法，自定义输出