java - 如何使用两个类将两个整数相乘，第一类包含方法 int calculateMultiplication (int, int)，第二类包含主要方法？

Question

我需要这个程序的帮助。我需要将用户输入的两个整数相乘，然后使用int calculateMultiplication (int, int)方法计算结果。第一个类包含变量和方法的声明，第二个类包含所有打印的主方法。我不知道如何调用 calculateMultiplication 方法在我的最终打印中实现，它给出“第一个用户输入（我得到）和第二个用户输入（我得到）的乘法是结果（我没有）。

public class JavaApplication19 {

    public static void main(String[] args) {
        
    Scanner input = new Scanner (System.in);
    System.out.print("Enter the first int number: ");
    int num1 = input.nextInt();
    Two Num1 = new Two();
    Num1.setN1 (num1);
    int numOne = Num1.getN1();
    
    System.out.print("Enter the second int number: ");
    int num2 = input.nextInt();
    Two Num2 = new Two();
    Num2.setN2 (num2);
    int numTwo = Num2.getN2();  
    }
}  
    
This is the part I need help on: (this is just what i have so far)

    System.out.println("The multiplication of " + numOne + " and " + numTwo + " is" + product + "." );
    Two Result = new Two();
    int result = Result.calculateMultiplication(num1, num2);

class Two {
 
    private int result;
    private int n1;
    private int n2;
    
    public int getN1(){
        return n1;
    }
    
    public void setN1(int _n1){
        n1 = _n1;
    }
    
    public int getN2(){
        return n2;
    }        
    
    public void setN2(int _n2){
        n2 = _n2;
    }
    
    
    public int calculateMultiplication(int n1, int n2){
        int answer = this.n1 * this.n2;
        return result;
    
    }
    
}

标签： java

Answer 1

注意实例变量和方法参数。

这两个类的写法可能有点不同：

public class Two {
    private int n1;
    private int n2;
    private int result;
    public void setN1(int n1) {
        this.n1 = n1;
    }
    public void setN2(int n2) {
        this.n2 = n2;
    }
    public void multiply() {
        this.result = this.n1 * this.n2;
    }
    public int getResult() {
        return this.result;
    }
}

它有两个私有int实例变量，n1和n2.

int num1 = 10; // for example
int num2 = 20; // for example

Two two = new Two();
two.setN1(num1);
two.setN2(num2);
two.multiply();
int result = two.getResult();

从这里你可以对这些值做任何你需要的事情。