Only Integer-type Values

If you need to select among several options based on complicated requirements, use nested if statements, or if else if statments (which are really the same thing.) Here is the previous program, re-written with equivalent if else if statments.

import java.io.*;
class Switcher
{
  public static void main ( String[] args ) throws IOException
  {
    String lineIn;
    char   color  ;    
    String message = "Color is";
    
    BufferedReader stdin = new BufferedReader
      ( new InputStreamReader(System.in) );

    System.out.println("Enter a color letter:");
    lineIn = stdin.readLine();
    color = lineIn.charAt( 0 );  // get the first character

    if      ( color=='r' || color=='R' )    
      message = message + " red" ;

    else if ( color=='o' || color=='O' )               
      message = message + " orange" ;
               
    else if ( color=='y' || color=='Y' )               
      message = message + " yellow" ;
               
    else if ( color=='g' || color=='G' )               
      message = message + " green" ;
               
    else if ( color=='b' || color=='B' )               
      message = message + " blue" ;

    else if ( color=='v' || color=='V' )               
      message = message + " violet" ;

    else 
      message = message + " unknown" ;
            
    System.out.println ( message ) ;
  }
}