在java中的扫描仪将不匹配我的双变量

Question

我已经搜索了大约一个小时，并且还没有找到解决我的问题。我试图使用我的扫描器变量输入来稍后将它用于我的开关参数，但是我现在被困在第二行上，正确的语法是为了让我的问题正常工作。 这里是我的Java问题：

//创建KW输入扫描仪

Scanner kw = new Scanner(System.in); 
    double kwUsed = kw; 

    //Verify if KW is valid 
    try 
    { 
     //KW used data entry 
     System.out.println("Please enter KW used: "); 
     kwUsed = kw.nextDouble(); 
     System.out.println("KW entry valid"); 
    } 
    catch (Exception error) 
    { 
     System.out.println("Invalid entry"); 
     System.out.println(error); 
    } 

    //Date entry will be calculated by how much KW user enters 
    switch (input) 
    { 
     case "2/15/13": 
      double quarter1 = kwUsed * 0.10; 
      break; 
     case "4/15/13": 
      double quarter2 = kwUsed * 0.12; 
      break; 
     case "8/15/13": 
      double quarter3 = kwUsed * 0.15; 
      break; 
     case "11/15/13": 
      double quarter4 = kwUsed * 0.15; 
      break; 
     default: 
      System.out.println("Invalid date"); 

    } 

Answer 1

只想常说我不会只是修复某人的代码，然后将其粘贴，但在这种情况下，我觉得它的更好地让OP看到一些制造的小错误，而不是漫不经心。

import java.util.Scanner; 
import java.io.IOException; 
import java.io.FileReader; 
import java.io.File; 
import java.io.BufferedReader; 

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

     Scanner kw = new Scanner(System.in); 
     double kwUsed = 0; 

     // Verify if KW is valid 
     try { 

      // KW used data entry 
      System.out.println("Please enter KW used: "); 
      kwUsed = kw.nextDouble(); 
      System.out.println("KW entry valid"); 
     } catch (Exception error) { 
      System.out.println("Invalid entry"); 
      System.out.println(error); 
     } 

     // Date entry will be calculated by how much KW user enters 
     String input; 
     System.out.println("Enter input case"); 
     input = kw.next(); 

     switch (input) { 
     case "2/15/13": 
      double quarter1 = kwUsed * 0.10; 
      break; 
     case "4/15/13": 
      double quarter2 = kwUsed * 0.12; 
      break; 
     case "8/15/13": 
      double quarter3 = kwUsed * 0.15; 
      break; 
     case "11/15/13": 
      double quarter4 = kwUsed * 0.15; 
      break; 
     default: 
      System.out.println("Invalid date"); 

     } 
      //handle your quarter1-4 here 
    } 
}