Switch

[Manish Pamnani]

Can't switch have a range as a case just like we do in if?

Like for example we can do if(i > 5 && i < 1)

can we do similiar things in switch?

If yes, then how?

[Campbell Ritchie]

Manish Pamnani wrote:Can't switch have a range as a case just like we do in if? . . .

Afraid not Sorry. Try if‑else if:-

if (score < 0 || score > 100)
{
   throw new IllegalArgumentException(...);
}
if (score < 20)
{
   grade = Grade.U;
}
else if (grade < 40)
{
   grade = Grade.F;
}
else if (grade < 50)
{
   grade = Grade.D;
}
else if (grade < 60)
{
   grade = Grade.C:
}
else if (grade < 70)
{
   grade = Grade.B;
{
else if (grade < 80)
{
   grade = Grade.A;
}
else
{
   grade = Grade.A_PLUS;
}

[Michael Krimgen]

You could use a switch with an enum. This could be an option if you want to reuse the conditions and keep the switch short.
Here is a simplified example. Please note that I do not advocate this pattern, but it might be appropriate in some cases.

public class Switch {

    public static void main(String[] argv) {
        int i = 5;

        switch(Compare.getByValue(i)) {
            case RANGE_1_5: System.out.println("one to five"); break;
            case RANGE_8_12: System.out.println("eight to twelve"); break;
            default: System.out.println("default value");
        }
    }

    private enum Compare {
        //do not add overlapping values
        RANGE_1_5(1,5), RANGE_8_12(8,12), DEFAULT(0,-1);
        int startRange, endRange;

        Compare(int start, int end) {
            startRange = start;
            endRange = end;
        }

        public static Compare getByValue(int i) {
            for(Compare c : Compare.values()) {
                if( i <= c.endRange && i>= c.startRange) {
                    return c;
                }
            }
            return DEFAULT;
        }

    }
}

[Campbell Ritchie]

Clever idea. I am not sure that is what an enum was intended for, however.