將變量值傳遞給新方法

Question

我是Java的新手，並且似乎無法使我的方法正常工作，而不必將變量重置為'null'或新的Object值。 我需要的是讓用戶輸入轉入下一個方法。

public static void addItem ()
{
    Scanner console = new Scanner(System.in);

    String desc, id, str="";
    double price = 0, setUpPrice = 0, unitCost = 0, inventoryCost = 0;
    int stock = 0, demand = 0;
    Product product  = new Product();


    System.out.print("Please enter product description between 3 to 10 characters...: ");
    desc = console.next();
    desc = desc.toLowerCase();
    product.setName(desc);


    /*if (desc.length < 3 || desc.length > 10)
    {
        System.out.print("This Input is incorrect, Please try again.");
    }*/
    System.out.print("Please enter price in $ : ");
    price = console.nextDouble();
    System.out.print("Please enter set up price. $ : ");
    setUpPrice = console.nextDouble();
    System.out.print("Please enter unit- cost. $ : ");
    unitCost = console.nextDouble();
    System.out.print("Please enter the inventory cost. $ : ");
    inventoryCost = console.nextDouble();
    System.out.print("Please enter the amount in stock : ");
    stock = console.nextInt();
    System.out.print("Please enter the demand of the product : ");
    demand = console.nextInt();


    // need code here to repeat the fuction again if y is pressed.
    // if n is pressed need to return to inventory management interface.

}

public static void prodData ()
{
    Product product = new Product();

    System.out.println("The information for the product is : ");
    System.out.println("Product description : "+product.getName());
}

Answer 1

將您的產品變量聲明為全局變量，並按以下方式訪問

    public static  Product product; 

public static void addItem () {
    product  = new Product();
    Scanner console = new Scanner(System.in);

    String desc, id, str="";
    double price = 0, setUpPrice = 0, unitCost = 0, inventoryCost = 0;
    int stock = 0, demand = 0;

    System.out.print("Please enter product description between 3 to 10 characters...: ");
    desc = console.next();
    desc = desc.toLowerCase();
    product.setName(desc);


    /*if (desc.length < 3 || desc.length > 10)
    {
        System.out.print("This Input is incorrect, Please try again.");
    }*/
    System.out.print("Please enter price in $ : ");
    price = console.nextDouble();
    System.out.print("Please enter set up price. $ : ");
    setUpPrice = console.nextDouble();
    System.out.print("Please enter unit- cost. $ : ");
    unitCost = console.nextDouble();
    System.out.print("Please enter the inventory cost. $ : ");
    inventoryCost = console.nextDouble();
    System.out.print("Please enter the amount in stock : ");
    stock = console.nextInt();
    System.out.print("Please enter the demand of the product : ");
    demand = console.nextInt();

    // need code here to repeat the fuction again if y is pressed.
    // if n is pressed need to return to inventory management interface.

}

public static void prodData () {
    System.out.println("The information for the product is : ");
    System.out.println("Product description : "+product.getName());
}