//question of round-up//

[chao-long liao]

In a switch statement, the argument to the case( case(argument) )can be any variable which can fit within an int??
Ans:false, the case argument must be either an int literal, or an int-compatible variable which is a constant.
What's the meaning??I can't understand what it says??

[Anthony Villanueva]

According to Mughal, p. 137:

The type of the integral expression [for switch] must be char, byte, short or int. The case label values must be assignable to the type of the integral expression. In particular, the case label values must be in the range of the type of the integral expression. Note that the type of the case label cannot be boolean, long or floating-point.

[Marilyn de Queiroz]

The case argument must be either an int literal, or an int-compatible variable which is a constant.

The case argument must be a constant. It can be an int literal ( like 1 , 2 , 3 ... ) or it can be a variable which has been declared as a constant ( like final int myCase = 2 ).

If it is a variable, it must be "final" (constant) and it must fit into an int (it can be a byte, short, char, or int). A long, float, double or boolean won't compile.

[Dan Chisholm]

The constant case expressions can be any expression that is assignable to the type of the switch expression.

 
class Green {
  public static void main(String args[]) {
    short[] s = {1, -1, 3, 4};
    for (int i = 0; i<s.length;i++) {
      switch(s[i]) {
        case 2-1: System.out.print("v ");
        break;
        case 'd'-'a': System.out.print("w ");
        break;
        case 0: System.out.print("x ");
        break;
        case ~0: System.out.print("y ");
        break;
        case 4&5: System.out.print("z ");
        break;
        default: System.out.print("Default ");
      }
    }
  }
}
What is the result of attempting to compile and run the above program? 
a.  Prints: v w x y 
b.  Prints: v w x y z Default 
c.  Prints: v y w z 
d.  Prints: Default Default Default Default  
e.  Runtime Exception 
f.  Compiler Error 
g.  None of the Above 

Prints: v y w z
Note: 'd'-'a'=3, ~0=-1, 4&5=4.