使用用户输入来调用整数

Question

我是编码的初学者，我正在尝试创建一个简单的程序，当读者键入他们的姓名时，该程序将显示他们欠的钱。 我当时正在考虑使用Scanner ， next(String)和int 。

import java.util.Scanner;

public class moneyLender {
  //This program will ask for reader input of their name and then will output how much 
  //they owe me. (The amount they owe is already in the database)

  public static void main(String[] args) {

    int John = 5; // John owes me 5 dollars
    int Kyle = 7; // Kyle owes me 7 dollars

    //Asking for reader input of their name
    Scanner reader = new Scanner(System.in);
    System.out.print("Please enter in your first name:");
    String name = reader.next();

    //my goal is to have the same effect as System.out.println("You owe me " + John);
    System.out.println("You owe me: " + name) // but not John as a string but John 
                                              // as the integer 5

    //Basically, i want to use a string to call an integer variable with 
    //the same value as the string. 



  }

}

Answer 1

作为一个初学者，您可能想使用一个简单的HashMap ，它将这些映射存储为键，值对。 Key将是name ， value将是money 。 这是示例：

import java.util.HashMap;
import java.util.Map;
import java.util.Scanner;

public class moneyLender {
  public static void main(String[] args) {

    Map<String, Integer> map = new HashMap<String, Integer>();
    map.put("John", 5);
    map.put("Kyle", 7);

    Scanner reader = new Scanner(System.in);
    System.out.print("Please enter in your first name:");
    String name = reader.next();

    System.out.println("You owe me: " + map.get(name)); //  
  }    
}

输出：
请输入您的名字：约翰
你欠我：5

Answer 2

如果要以字符串形式读取用户输入，则最好使用nextLine（）方法。

您还希望创建一个使用String参数（即名称）并返回所欠金额的方法。

public int moneyOwed(String name){      
       switch(name){

case "Kyle": return 5;

case "John": return 7;

    }
}

    public static void main(String[] args) {

        int John = 5; // John owes me 5 dollars
        int Kyle = 7; // Kyle owes me 7 dollars


        Scanner reader = new Scanner(System.in);
        System.out.print("Please enter in your first name:");
        String name = reader.nextLine();


        System.out.println(name +" owes me " + moneyOwed(name) + " dollars");
        }