Using break

There is one label per case statement, and there must be an exact match with the expression in the switch for the case to be chosen.

The break at the end of each case is not always needed. If it is omitted, then after the statements in the selected case have executed, execution will continue with the following case. This is not usually what you want. Examine the following program:

class Switcher
{
  public static void main ( String[] args )
  {
    char   color = 'Y' ;    
    String message = "Color is";
    
    switch ( color )
    {
    
      case 'R':
        message = message + " red" ;
                        
      case 'O':
        message = message + " orange" ;
                        
      case 'Y':
        message = message + " yellow" ;
                        
      case 'G':
        message = message + " green" ;
                        
      case 'B':
        message = message + " blue" ;
                        
      case 'V':
        message = message + " violet" ;
                        
      default:
        message = message + " unknown" ;
            
    }

  System.out.println ( message ) ;
  }
}

The program fragment will print:

Color is yellow green blue violet unknown

This is probably not what the program was intended to do.