Question

Which is the best way to set an array of n dimensions from a function?

var v1 = [1,2,3];
var v2 = [[1,2],[3,4]];

// only valid for 1-dimension
function set(arr, dim, v) {
    arr[dim] = v;
}

set(v1, 2, 33);

Answer 1

Your function can’t work as designed it needs an index for each dimension

You’d need something like the following http://jsfiddle.net/nZmJT/1/

function setValueInArray(arr, value, index /*, index, index, ... */ ) {
    var arrToSet = arr;
    for (var i = 2; i < arguments.length - 1; i++) {
       arrToSet = arr[arguments[i]];
    }
    arrToSet[arguments[i]]= value;
    return arr;
}


var v1 = [1,2,3];
var v2 = [[1,2],[3,4]];

console.log( setValueInArray(v1, 0, 0) ); // [0,2,3]
console.log( setValueInArray(v2, 0, 0, 0) ); //[[0,2],[3,4]]

Please share with us why you’d like this. I can’t think of code that can be generalized to work with multiple dimensions, you usually know the dimension, and just set it like…

v1[2][3] = 'anything';

Since in your case, you wouldn’t know how many indexes to pass (otherwise you’d just use bracket access), the following may be a better fit

function setValueInArray(arr, value, indexes) {
    var arrToSet = arr;
    for (var i = 0; i < indexes.length - 1; i++) {
       arrToSet = arr[indexes[i]];
    }
    arrToSet[indexes[i]] = value;
    return arr;
}

Then you can call it passing the array of indexes which is created by some code outside of your control.

setValueInArray(v1, 0, indexes);