Convert between different number bases. No radix of 36 restriction

convert_number_bases.js

/**
 * Convert a number to base 10 give a base and a number array
 * @param {int[]} n_array
 * @param {int} base
 * @returns {int}
 */
var to_base10 = function(n_array, base) {
    n_array.reverse();
    var n = 0;
    for(var i=0, l=n_array.length; i<l; i++) {
        n += Math.pow(base, i)*n_array[i];
    }
    return n;
};

/**
 * Convert a number from base 10 give a base number and a base
 * @param {int} n
 * @param {int} base
 * @returns {int[]}
 */
var from_base10 = function(n, base) {
    var n_array = [];
    //the number place
    var num_place = 0;
    //start
    while(n > 0) {
        //1. divide by the base
        var rem = n%base;
        //2. remove the remainder
        n -= rem;
        //add the remainder to the appropriate number place
        n_array[num_place] = rem;
        //move to the next number place
        num_place++;
        //divide out this number place
        n /= base;
    }
    return n_array.reverse();
};

/**
 * Converts a number array using a map
 * @param {int[]} n_array
 * @param {String} map
 * @returns {String}
 */
var to_map = function(n_array, map) {
    var n = [];
    for(var i=0, l=n_array.length; i<l; i++) {
        n.push(map.charAt(n_array[i]));
    }
    return n.join('');
};

/**
 * 
 * @param {String|Number} n
 * @param {String} map
 * @returns {int[]}
 */
var from_map = function(n, map) {
    n = String(n);
    var n_array = [];
    var map_array = map.split('');
    for(var i=0, l=n.length; i<l; i++) {
        n_array[i] = map_array.indexOf(n.charAt(i));
    }
    return n_array;
};


//Usage
var base = 70;
var m = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz!@#$%^&*';

var b = from_base10(110216557474, base);
console.log(b);
//[ 65, 40, 31, 4, 69, 44 ]

var f = to_map(b, m);
console.log(f);
//$eV4*i

var k = to_base10(b, base);
console.log(k);
//110216557474

var q = from_map('8F', m);
console.log(q);
//[ 8, 15 ]

var r = to_base10(q, 16);
console.log(r);
//143