Question

I’m creating a javascript battleships game. The game works fine. I have created the game so that the user has a maximum of 25 misses – if they reach 25 then it’s game over.

I now want to create a function that at the end of the game, the function checks the number of misses, and alerts the user their score and rank name.

I calculated the score by ((25/misses)*100).

So these are the possible scores with misses.

Misses | Score
(1 |2500)
(2 | 1250)
(3 | 833)
(4 | 625)
(5 | 500)
(6 | 417)
(7 | 357)
(8 | 313)
(9 | 278)
(10 | 250)
(11 | 227)
(12 | 208)
(13 | 192)
(14 | 179)
(15 | 167)
(16 | 156)
(17 | 147)
(18 | 139)
(19 | 132)
(20 | 125)
(21 | 119)
(22 | 114)
(23 | 109)
(24 | 104)
(25 | 0)

The rank names I have are
1) Admiral of the Fleet
2) Admiral
3) Vice-Admiral
4) Rear-Admiral
5) Commodore
6) Killed In Action

These are how i’ve assigned the misses with the rank names.

Misses | Rank Name
(0-12 | Admiral of the Fleet)
(13-15 | Admiral)
(16-19 | Vice-Admiral)
(20-24 |Commodore)
(25 | Kill In Action)

I have created a variable named ‘misses’. Each time you miss, obviously the variable increments by one.

So let’s say you just played and finished the game with 14 misses. I want the function to check the variable ‘misses’ and then assign it with the appropriate score and rank.

I reckon I could probably use an array for the misses with score. Any ideas what the exact code is? please help!

Answer 1

Simplest solution:

function getRank(misses) {
    if (misses < 13)
        return 'Admiral of the Fleet';
    if (misses < 16)
        return 'Admiral';
    if (misses < 20)
        return 'Vice-Admiral';
    if (misses < 25)
        return 'Commodore';
    return 'Killed In Action';
}

You could also do something like this, which is more complicated and uses more memory, but would result in a faster getRank() – and if you won’t have over 25 misses, the memory usage won’t be a problem.

var getRank = (function () {
    var rank, i = 0, j,
        map = {},
        ranks = [
            [13, 'Admiral of the Fleet'],
            [16, 'Admiral'],
            [20, 'Vice-Admiral'],
            [25, 'Commodore'],
            [26, 'Killed In Action']
        ];
    for (j = 0; rank = ranks[j]; j++)
        for (; i < rank[0]; i++)
            map[i] = rank[1];
    return function (misses) {
        return map[misses];
    };
})();