20145306实验二java面向对象程序设计

实验目的

设计实现复数类。

Complex复数类的方法有：构造函数、返回复数内容，以及复数间相加、减、乘运算。

加法：实部相加，虚部相加，最后以虚数的形式返回 减法：实部相减，虚部相减，最后以虚数的形式返回 乘法：实部相乘减去虚部相乘返回实部，实部虚部交错相乘后相加返回虚部，最后返回虚数形式 Complex类：

public class Complex {

protected int a;

protected int b;

public Complex(int a,  int b) {
    this.a = a;
    this.b = b;
}

public String toString() {
    return this.a + " + " + this.b + "i";
}

public static Complex addition(Complex complex1, Complex complex2) {
    int a = complex1.a + complex2.a;
    int b = complex1.b + complex2.b;
    return new Complex(a, b);
}

public static Complex subtract(Complex complex1, Complex complex2) {
    int a = complex1.a - complex2.a;
    int b = complex1.b - complex2.b;
    return new Complex(a, b);
}

public static Complex multiplication(Complex complex1, Complex complex2) {
    int a = complex1.a * complex2.a - complex1.b * complex2.b;
    int b = complex1.b * complex2.a + complex1.a * complex2.b;
    return new Complex(a, b);
}


}

调用Complex类：

 public class Main {
      public static void main(String[] args) {
         Scanner scanner=new Scanner(System.in);
        System.out.println("输入个复数的实部和虚 部：");
        int a = scanner.nextInt();
        int b = scanner.nextInt();
        System.out.println("输入个复数的实部和虚部：");
        int c = scanner.nextInt();
        int d = scanner.nextInt();
        Complex fushu1=new Complex(a,b);
        Complex fushu2=new Complex(c,d);
        while(true) {
            System.out.println("输入1.2.3.4.进行加减乘除运算");
            int w = scanner.nextInt();
            switch (w) {
                case 1:
                    System.out.println(Complex.addition(fushu1, fushu2));
                    break;
                case 2:
                    System.out.println(Complex.subtract(fushu1, fushu2));
                    break;
                case 3:
                    System.out.println(Complex.multiplication(fushu1, fushu2));
                    break;


                default:System.out.println("erorr");
            }
        }
    }
 }

测试代码

public class test {
 public static void main(String[] args) {
        Complex complex1 = new Complex(1, 2);
        Complex complex2 = new Complex(3, 4);
        if(Complex.addition(complex1, complex2).a!=4||Complex.addition(complex1, complex2).b!=6)
            System.out.println("addition test failed ");
        else
            System.out.println("addition test passed");

        if(Complex.subtract(complex1, complex2).a!=-2||Complex.subtract(complex1, complex2).b!=-2)
            System.out.println("substract test failed");
        else
            System.out.println("substract test passed");

        if(Complex.multiplication(complex1, complex2).a!=-5||Complex.multiplication(complex1, complex2).b!=10)
            System.out.println("multiplication test failed");
        else
            System.out.println("multiplication test passed ");
    }
}

单元测试

用Star UML 建模

PSP