Why use the switch statment instead of if else statments?

Question

Switches seem so useless as they can be replaced with if-else statements, which can do much more than just match a char/int/enum etc. I can only think of one good use for a switch, and that would be for interpreting command line args.

What are some realistic uses for a switch statement?

Answer 1

There are a few cases where switch is more readable and comes in handy. Usually when you have grouping of options.

Here is one of them:

    int numDays = 0;
    int month = 2;
    int year = 2010;

    // find the number of days in the month
    switch (month) {
        case 1:
        case 3:
        case 5:
        case 7:
        case 8:
        case 10:
        case 12:
            numDays = 31;
            break;
        case 4:
        case 6:
        case 9:
        case 11:
            numDays = 30;
            break;
        case 2:
            if ( ((year % 4 == 0) && !(year % 100 == 0))
                 || (year % 400 == 0) )
                numDays = 29;
            else
                numDays = 28;
            break;
        default:
            System.out.println("Invalid month.");
            break;
    }