title: why variable have to be initialized?
body: <p>here i tried to get output month by inputting month number but why i am having error 
   - "monthString" mightn't have been initialized ? 
   - and why i am not getting output string  from " monthString "?</p>
  
  <h1>why monthString have to be initialized ?</h1>
  
  <pre><code>import java.util.Scanner;
  public class SwitchClass {
  
  public static void main(String[]args)
  {
     Scanner input = new Scanner(System.in);
     System.out.printf(" when did u born ? ");
     int monthNumber = input.nextInt();
     String monthString ;
  
  switch (monthNumber)
  {
      case 1:
      monthString = "January ";
          break;
      case 2:
          monthString = "February ";
          break;
      case 3:
          monthString = "March ";
          break;
      case 4:
          monthString = "April ";
          break;
      case  5:
          monthString = "May";
          break;
      case  6:
          monthString = "June";
          break;
      case  7:
          monthString = "July";
          break;
      case  8:
          monthString = "August";
          break;
      case  9:
          monthString = "September";
          break;
      case  10:
          monthString = "October";
          break;
      case  11:
          monthString = "November";
          break;
      case  12:
          monthString = "December";
          break;
     }
  System.out.println(monthString);       }
  
   }
  </code></pre>