Converting from base 10 beginner

Question

I was asked to write code that helps to go from base 10 to any other base. So far I have this

var y=23 //Number in base 10 I want to convert
var x=2 //Base I want to convert to 
var r=[]
if(y>=x){
r.push(y%x)
var y=(Math.floor(y/x))
}
else {
r.push(y)    
}
console.log(r)

Sorry if this is to basic i need to keep it simple thanks for the help

Answer 1

Use these codes:

var digits = [
  '0','1','2','3','4','5','6','7','8','9',
  'A','B','C','D','E','F','G','H','I','J',
  'K','L','M','N','O','P','Q','R','S','T',
  'U','V','W','X','Y','Z'
];

/**
 * x is the base, y is the decimal value
 * x must be in the range of 2..36
 * y must be greater than zero
 */
function base10ToBaseN(x,y) {
  var str = "";

  while (y>0) {
    var mod = y%x;
    var div = Math.floor(y/x);

    str = digits[mod]+str;
    y   = div;
  }

  return str;
}

alert(base10ToBaseN(2,23));

See this jsfiddle: http://jsfiddle.net/jondinham/mLz5ycey

Answer 2

function convertToBase(input, base){
    var digits = [];
    while(digits.push(letter(input%base)), input = (input/base)|0)     //work for int
    function letter(n){ return n > 9 ? String.fromCharCode(n%base+55) : n;}
    return digits.reverse().join("");
}

convertToBase(255,16);        //FF
convertToBase(255,2);         //11111111

---

You can even attach this to the Number prototype for extra fun.

Number.prototype._ = function(b){ return convertToBase(this, b); };

255.._(16);       //FF
255.._(2);        //11111111
//Doesn't look like JavaScript's syntax anymore :)

However note that this only work for ∀n ∈ ℤ, n ≥ 0. Demo: http://jsfiddle.net/DerekL/nxf6wpkz/

---

Why do mathematicians claim that Halloween is the same as Christmas?

Because convertToBase(25, 8).

Oct 31 = Dec 25