Question

I have looked around and cannot find a working solution to my problem.

Background — the intended use is an easy to form for a live rpg group for calculating successes of a downtime action. By entering numbers into given form fields, the script calculates the total number of “dice” with values between 1 – 10 to be used. There is also a difficulty threshold that needs to be met on each “roll” of the “dice” to be considered a success.

I am having difficulties generating random numbers using totalDice as the size of the array. Once I have that down, I will need to find a way to count and display the total number of random numbers greater than the given difficulty threshold.

For a working example of what I have so far, see here.

I have a var = totalDice which provides the size of the random array. The values of the random numbers are 1 – 10.

For example, if totalDice= 220, I need 220 random numbers generated between 1 and 10.
Then I have var = totalDiff which provides a threshold that I need to compare against the random numbers generated. I need to find a way to take the array generated and count the number of instances that are => totalDiff.

Example: totalDice = 220, totalDiff = 6, totalSuccesses = x, where x = the number of elements => 6.

Any help is greatly appreciated.

Answer 1

Break this into chunks, that’s what functions are for.

var roll = function() {
    return Math.floor(Math.random() * 10 + 1);
};

var getResult = function(difficulty) {
    return roll() >= difficulty;
};

var getAllResults = function(totalDice, difficulty) {
    var arr = [];
    for (var i = 0; i < totalDice; i++) {
        arr.push(getResult(difficulty));
    }
    return arr;
};

Check:

var results = getAllResults(220, 6);
var t = 0;
var f = 0;

for (var i = 0; i < results.length; i++) {
    if (results[i]) { 
        t++;
    } else {
        f++;
    }
}
console.log('total rolls', 220);
console.log('total result count (expected 220)', results.length);
console.log('boolean results (expected 220)', t + f);
console.log('successes', t);
console.log('failures', f);
console.log('raw results array', results);

Edit: If you just want the number of successes, make another function to count them:

var getSuccesses = function(results) {
    var successes = 0;
    for (var i = 0; i < results.length; i++) {
        if (results[i]) { 
            successes++;
        } 
    }
    return successes;
};

//Count successes for 175 die rolls at difficulty 8:
var s = getSuccesses(getAllResults(175, 8));