java7-4 复数类的定义

在Java 7中，复数类的定义通常是通过`Complex`或`Pair`这样的命名来实现的，因为Java本身并不内置复数类型的原生支持。一个简单的复数类可能会像这样定义：

import java.util.Arrays;

public class Complex {
    private double real;   // 实部
    private double imaginary;   // 虚部

    // 构造方法，实部和虚部可以单独传递
    public Complex(double real, double imaginary) {
        this.real = real;
        this.imaginary = imaginary;
    }

    // 构造方法，从数组接收实部和虚部
    public Complex(double[] parts) {
        this(real: parts[0], imaginary: parts[1]);
    }

    // 获取复数属性
    public double getReal() { return real; }
    public double getImaginary() { return imaginary; }

    // 设定复数属性
    public void setReal(double real) { this.real = real; }
    public void setImaginary(double imaginary) { this.imaginary = imaginary; }

    // 重载加法、减法、乘法和除法等操作符
    public Complex add(Complex other) { ... }
    public Complex subtract(Complex other) { ... }
    public Complex multiply(Complex other) { ... }
    public Complex divide(Complex other) throws ArithmeticException { ... }

    // 显示复数为 "a + bi"
    @Override
    public String toString() {
        return String.format("%.2f + %.2fi", real, imaginary);
    }
}