Hash to small integer

gistfile1.js

// Hash 'string' to a small number (digits default: 6)
function hash(string, digits) {
  digits = digits || 6;
  var m = Math.pow(10, digits+1) - 1;
  var phi = Math.pow(10, digits) / 2 - 1;
  var n = 0;
  for (var i = 0; i < string.length; i++) {
    n = (n + phi * string.charCodeAt(i)) % m;
  }
  return n.toString();
}