我开始了我的Java编码经验，我试图用数组和方法编写一个杂货店结帐程序

Question

    //Initializing scanner declaring arrays
    Scanner scan= new Scanner (System.in); 
    int quantity[]=new int[3];
    String name[]=new String[3];
    double price[]=new double [3];

    //do while loop to continue entering items until quantity is 0
    do
    {

        System.out.println("Enter quantity of item, " + "name of item, " + " and price of item, " );
        quantity[i]= scan.nextInt();
        name[i]=scan.next();
        price[i]=scan.nextDouble();
        i++;
    }while(quantity[i]==0);


    //menu for grocery list operations using switch block
    System.out.println("1) Add item(s)/n"
            + "2) Remove item(s)/n"
            + "3) view cart/n "
            + "4) Checkout/n "
            + "5) Exit/n");
    ch=scan.nextInt();
    switch(ch) 
    {
    case 1: 


        add(quantity[i-1],name[i-1],price[i-1]);
        break;

下面是方法add

//method to add item
public static  void add(int q,String  n,double p )

{
    Scanner scan= new Scanner (System.in);
    System.out.println("Enter quantity of item, " + "name of item, " + " and price of item, " );
    q=scan.nextInt();
    n= scan.next();
    p=scan.nextDouble(); 
    scan.close();


}

Answer 1

在java中，将数组作为参数传递和返回数组非常简单。

下面是一个例子：

public static int[] foo(int[] a){
    // Do something with a
    int[] b = {0,1,2};
    return b;
}

但也要记住，Java是按值传递的，但是当您将数组作为参数传递时，它将引用（也称为内存地址）作为值传递给函数。

public static void main(String... args){
    int b = 5;
    foo1(b);
    // b is still 5


    int[] c = {1,2};
    foo2(c);
    // c is now {1,10} 
}

public static void foo1(int x){
    x = 10;
}

public static void foo2(int[] x){
    x[1] = 10;
}