Question

I am currently working on a random number generator script that will generate three numbers. The first two numbers will be used to pick a “cell” in a “table” by referencing the row and column. Within each cell are two numbers to choose from. The third number will then determine which of the two numbers to select. I have figured out most of this but I am having problems with the last part.

My “solution” was to create twenty arrays, and within each array are twenty more arrays. Here is an example of the first array:

In the header I have the following:

Scripts to generate the first two numbers:

var randOne20 = Math.floor(Math.random()*20);
var randTwo20 = Math.floor(Math.random()*20);

Here is the first row of the 20 arrays:

var lvl1Roll1 = [[ 1,0 ],[ 1,1 ],[ 1,2 ],[ 1,3 ],[ 1,4 ],[ 1,5 ],[ 1,6 ],[ 1,7 ],[ 1,8 ],[ 1,9 ],[ 1,10 ],[ 1,11 ],[ 1,12 ],[ 1,13 ],[ 1,14 ],[ 1,15 ],[ 1,16 ],[ 1,17 ],[ 1,18 ],[ 1,19 ]];

The second row would be “lvl1Roll2” and the third would be “lvl1Roll3” etc. all the way up to “lvl1Roll20.”

In the body I have the following script:

var randOne = randOne20 + 1;

document.write(window['lvl1Roll'+randOne][randTwo20]);

The randOne variable is used to select the appropriate row.

I can figure out how to select a specific cell (using the randTwo20 variable) but I have no idea how to then select the first or the second number within each cell.

Now, just to clarify, I have not listed the third random number generator code because at the moment I am just trying to figure out how to select either the first or second number within each cell. Once I figure that out I can just use an if/else statement.

Also, if I did not want to print out the number but select it as a variable how would I do that?

Thank you for any and all help!

Take care and have a great day….

ciao,
john.

Answer 1

I’m really not sure what you’re trying to do, but… Getting the first of second element of an array is as simple as arr[0] and arr[1], like so:

// First:
document.write(window['lvl1Roll'+randOne][randTwo20][0]);

// Second:
document.write(window['lvl1Roll'+randOne][randTwo20][1]);

To randomize, just follow the same pattern as before, but use Math.round instead of Math.floor and don’t multiply by 20:

var randOne20 = Math.floor(Math.random()*20);
var randTwo20 = Math.floor(Math.random()*20);
var randOne = Math.round(Math.random());

document.write(window['lvl1Roll'+randOne20][randTwo20][randOne]);

One more thing, though: you don’t need to put the different rows in separate variable. You can just make it one big array:

var lvl1Roll = [
    [
        [ 1,0 ], [ 1,1 ], [ 1,2 ], [ 1,3 ], [ 1,4 ], [ 1,5 ], [ 1,6 ], [ 1,7 ], [ 1,8 ], [ 1,9 ], [ 1,10 ], [ 1,11 ], [ 1,12 ], [ 1,13 ], [ 1,14 ], [ 1,15 ], [ 1,16 ], [ 1,17 ], [ 1,18 ], [ 1,19 ]
    ],
    // [ lvl1Roll2 ],
    // [ lvl1Roll3 ], etc.
];

And use then use this to select a value from the table and put it into the variable result:

var result = lvl1Roll[randOne20][randTwo20][randOne];

And finally: I suspect that, I you were to tell us the logic behind the “rolls”, it’s quite plausible that you don’t need this “table” at all. I could be wrong, but… might it be worth posting another question about that? Just a thought.