如果有多个 IF 语句，如何返回 1 个字符串

Question

如果我有一些 IF 语句，我如何返回 1 个值？

例如，当我选择 Shopify 时，它会调用一个新方法，该方法允许我在控制台中输入一些需要的凭据，然后将所有输入的数据附加到 1 个字符串中，并将该字符串（测试）返回给 Main 类。 如果我选择 Bigcommerce，它会调用几乎相同的方法，并将 Biggcomerce 所需的所有凭据也附加到 1 String(test2) 中。但在这种情况下， public String credentailsCollector() 应该返回 test2。

我该怎么做？谢谢。

public class CartCredentialsCollector {
//it should return something like this: 
//store_url=https://test.myshopify.com&apiKey=myapikey&apiPassword=myapipassword

public String credentailsCollector() throws IOException {

    BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));

    System.out.println("Do you want to connect a new shopping cart ('yes'/'no')");
    String newConnection = bufferedReader.readLine();
    if (newConnection.equals("no")) {
        bufferedReader.close();
    } else {
        System.out.println("Specify your shopping cart. It works with Shopify and Bigcommerce only");
        String newShoppingCart = bufferedReader.readLine();
        if (newShoppingCart.equals("Shopify")) {
            ShopifyCredentialsHandler sch = new ShopifyCredentialsHandler();
            String test = sch.shopifyCredentialsHandler();
        }
        else if (newShoppingCart.equals("Bigcommerce")) {
        BigcommerceCredentialsHandler bch = new BigcommerceCredentialsHandler();
        String test2 = bch.bigcommerceCredentialsHandler()
        }

        else {
            System.out.println("This method works with Shopify and Bigcommerce. Try to connect a Shopify or Bigcommerce store.");
            bufferedReader.close();
        }
    }
    // Here I need to return test (in case I choose "Shopify") or test2 (in case I choose "Bigcommerce"). How can I do that?
    }
}

Answer 1

您可以使用方法范围的字符串变量并设置它的值，而不是两个不同的字符串变量。像这样的：

public class CartCredentialsCollector {
//it should return something like this: 
//store_url=https://test.myshopify.com&apiKey=myapikey&apiPassword=myapipassword

public String credentailsCollector() throws IOException {
    String test = null;
    BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));

    System.out.println("Do you want to connect a new shopping cart ('yes'/'no')");
    String newConnection = bufferedReader.readLine();
    if (newConnection.equals("no")) {
        bufferedReader.close();
    } else {
        System.out.println("Specify your shopping cart. It works with Shopify and Bigcommerce only");
        String newShoppingCart = bufferedReader.readLine();
        if (newShoppingCart.equals("Shopify")) {
            ShopifyCredentialsHandler sch = new ShopifyCredentialsHandler();
            test = sch.shopifyCredentialsHandler();
        }
        else if (newShoppingCart.equals("Bigcommerce")) {
        BigcommerceCredentialsHandler bch = new BigcommerceCredentialsHandler();
        test = bch.bigcommerceCredentialsHandler()
        }

        else {
            System.out.println("This method works with Shopify. Try to connect a Shopify store.");
            bufferedReader.close();
        }
    }
    return test;
    // Here I need to return test (in case I choose "Shopify") or test2 (in case I choose "Bigcommerce"). How can I do that?
    }
}

Answer 2

您应该在 if 语句之前声明 test 或进行多次返回 - 每个 if 中返回一个。

Answer 3

正如您所意识到的，您无法访问要返回的“test”或“test2”变量的原因是因为它们当时都超出了范围。

您需要在顶部（在您的第一个 if 语句之前）声明一个字符串变量，其中变量的范围将扩展到整个 credentialsCollector() 方法，或者使用多个返回，将每个返回与您的“test”和“test2”变量。