We discussed conditionals earlier. With if statements containing boolean expressions in parenthesis. If you need to execute som code depending on various values of the same variable such as

'use strict';
...
res = roll(6);
if (res === 1)
    ones++;
else if (res === 2)
    twos++;
else if (res === 3)
    threes++;
else if (res === 4)
    fours++;
else if (res === 5)
    fives++;
else
    sixes++;
...

A fragment of the solution for the section called “Assignment JS.Conds.0”.

With a programming construct, switch, this could perhaps be done simpler:

'use strict';
...
res = roll(6);
switch (res) {
    case 1:
        ones++;
        break;
    case 2:
        twos++;
        break;
    case 3:
        threes++;
        break;
    case 4:
        fours++;
        break;
    case 5:
        fives++;
        break;
    case 6:
        sixes++;
        break;
}
...

or, equivalently

'use strict';
...
res = roll(6);
switch (res) {
    case 1:
        ones++;
        break;
    case 2:
        twos++;
        break;
    case 3:
        threes++;
        break;
    case 4:
        fours++;
        break;
    case 5:
        fives++;
        break;
    default:
        sixes++;
}
...

You must notice two things from the last example: There is a default clause that you may use similarly to the else from the first example. Until recently conventional wisdom dictated that using default, it must be placed last, just as its role model else, this does not longer seem to be the case. Reports from JavaScript and other languages seem to contradict that. Henceforth we shak recommend placing it last because it impoves readability.

switch (expression) {
case expression:
    statements
default:
    statements
}