BigNumber //JavaScript Class
Offers a extremely high precision level to make mathematical operations. For integers there is no limits and for floating point numbers, the class allows setting the maximum precision.
[UPDATED CODE AND HELP CAN BE FOUND HERE]
The class always returns new instances of BigNumber on the operations, so to the set value of a object, use the "set" method.
//+ Jonas Raoni Soares Silva //@ http://jsfromhell.com/classes/bignumber [v1.0] BigNumber = function(n, p, r){ var o = this, i; if(n instanceof BigNumber){ for(i in {precision: 0, roundType: 0, _sign: 0, _dec: 0}) o[i] = n[i]; o._buffer = n._buffer.slice(); return; } o.precision = isNaN(p = Math.abs(p)) ? BigNumber.defaultPrecision : p; o.roundType = isNaN(r = Math.abs(r)) ? BigNumber.defaultRoundType : r; o._sign = (n += "").charAt(0) == "-"; o._dec = ((n = n.replace(/[^\d.]/g, "").split(".", 2))[0] = n[0].replace(/^0+/, "") || "0").length; for(i = (n = o._buffer = (n.join("") || "0").split("")).length; i; n[--i] = +n[i]); o.round(); }; with({$: BigNumber, o: BigNumber.prototype}){ $.ROUND_HALF_EVEN = ($.ROUND_HALF_DOWN = ($.ROUND_HALF_UP = ($.ROUND_FLOOR = ($.ROUND_CEIL = ($.ROUND_DOWN = ($.ROUND_UP = 0) + 1) + 1) + 1) + 1) + 1) + 1; $.defaultPrecision = 40; $.defaultRoundType = $.ROUND_HALF_UP; o.add = function(n){ if(this._sign != (n = new BigNumber(n))._sign) return n._sign = !n._sign, this.subtract(n); var o = new BigNumber(this), a = o._buffer, b = n._buffer, la = o._dec, lb = n._dec, n = Math.max(la, lb), i, r; la != lb && ((lb = la - lb) > 0 ? o._zeroes(b, lb, 1) : o._zeroes(a, -lb, 1)); i = (la = a.length) == (lb = b.length) ? a.length : ((lb = la - lb) > 0 ? o._zeroes(b, lb) : o._zeroes(a, -lb)).length; for(r = 0; i; r = (a[--i] = a[i] + b[i] + r) / 10 >>> 0, a[i] %= 10); return r && ++n && a.unshift(r), o._dec = n, o.round(); }; o.subtract = function(n){ if(this._sign != (n = new BigNumber(n))._sign) return n._sign = !n._sign, this.add(n); var o = new BigNumber(this), x = o.compare(n) + 1, a = x ? o : n, b = x ? n : o, la = a._dec, lb = b._dec, n = la, i, j; a = a._buffer, b = b._buffer, la != lb && ((lb = la - lb) > 0 ? o._zeroes(b, lb, 1) : o._zeroes(a, -lb, 1)); for(i = (la = a.length) == (lb = b.length) ? a.length : ((lb = la - lb) > 0 ? o._zeroes(b, lb) : o._zeroes(a, -lb)).length; i;){ if(a[--i] < b[i]){ for(j = i; j && !a[--j]; a[j] = 9); --a[j], a[i] += 10; } b[i] = a[i] - b[i]; } return o._sign = !x, o._dec = n, o._buffer = b, o.round(); }; o.multiply = function(n){ var o = new BigNumber(this), r = o.compare(n = new BigNumber(n)) + 1, a = (r ? o : n)._buffer, b = (r ? n : o)._buffer, la = a.length, lb = b.length, x = new BigNumber, i, j, s; for(i = lb; i; x.set(x.add(new BigNumber(s.join(""))))) for(s = (new Array(lb - --i)).join("0").split(""), r = 0, j = la; j; r += a[--j] * b[i], s.unshift(r % 10), r = r / 10 >>> 0); return r && x._buffer.unshift(r), o._dec = (o._buffer = x._buffer).length - la - lb + o._dec + n._dec, o.round(); }; o.divide = function(n){ if((n = new BigNumber(n)) == "0") throw new Error("division by 0"); var o = new BigNumber(this), a = o._buffer, b = n._buffer, la = a.length - o._dec, lb = b.length - n._dec, s = a._sign != b._sign, dec = 0, buffer = [], x = new BigNumber, y, i; la != lb && ((lb = la - lb) > 0 ? o._zeroes(b, lb) : o._zeroes(a, -lb)); o._dec = a.length, n._dec = b.length; b = n, a._sign = false, b._sign = false; while(o != 0 && (buffer.length - dec) <= o.precision){ x.set(0); for(i = 0; o.compare(y = x.add(b)) + 1 && ++i; x.set(y)); if(!i){ do ++i, o._buffer.push(0), ++o._dec; while(o.compare(b) < 0); !dec && (!buffer.length && buffer.push(0), dec = buffer.length); o._zeroes(buffer, --i); continue; } o.set(o.subtract(x)), buffer.push(i); } return o._buffer = buffer, o._dec = dec ? dec : buffer.length, o.round(); }; o.mod = function(n){ return this.subtract(this.divide(n).intPart().multiply(n)); }; o.pow = function(n){ var o = new BigNumber(this), i; if(n == 0) return o.set(1); for(i = Math.abs(n); --i; o.set(o.multiply(this))); return n < 0 ? o.set((new BigNumber(1)).divide(o)) : o; }; o.set = function(n){ return this.constructor(n), this; }; o.compare = function(n){ var a = this, la = this._dec, b = n, lb = n._dec, i, l; if(la != lb) return la > lb ? 1 : -1; for(la = (a = a._buffer).length, lb = (b = b._buffer).length, i = -1, l = Math.min(la, lb); ++i < l;) if(a[i] != b[i]) return a[i] > b[i] ? 1 : -1; return la != lb ? la > lb ? 1 : -1 : 0; } o.negate = function(){ var n = new BigNumber(this); return n._sign ^= 1, n; }; o.abs = function(){ var n = new BigNumber(this); return n._sign = 0, n; }; o.intPart = function(){ return new BigNumber((this._sign ? "-" : "") + (this._buffer.slice(0, this._dec).join("") || "0")); }; o.valueOf = o.toString = function(){ var o = this; return (o._sign ? "-" : "") + (o._buffer.slice(0, o._dec).join("") || "0") + (o._dec != o._buffer.length ? "." + o._buffer.slice(o._dec).join("") : ""); }; o._zeroes = function(n, l, t){ var s = ["push", "unshift"][t || 0]; for(++l; --l; n[s](0)); return n; }; o.round = function(){ if("_rounding" in this) return this; var $ = BigNumber, r = this.roundType, b = this._buffer, d, p, n, x; for(this._rounding = true; this._dec > 1 && !b[0]; --this._dec, b.shift()); for(d = this._dec, p = this.precision + d, n = b[p]; b.length > d && !b[b.length -1]; b.pop()); x = (this._sign ? "-" : "") + (p - d ? "0." + this._zeroes([], p - d - 1).join("") : "") + 1; if(b.length > p){ n && (r == $.DOWN ? false : r == $.UP ? true : r == $.CEIL ? !this._sign : r == $.FLOOR ? this._sign : r == $.HALF_UP ? n >= 5 : r == $.HALF_DOWN ? n > 5 : r == $.HALF_EVEN ? n >= 5 && b[p - 1] & 1 : false) && this.add(x); b.splice(p, b.length - p); } return delete this._rounding, this; }; }
Usage
<script type="text/javascript"> var x = new BigNumber("10"), y = new BigNumber("-2"); alert(x.pow(y)); alert(x.pow(1234)); alert((new BigNumber("99999999999999999999999999999999999")).add("999999999999999999999999999.99999999999999999")); </script>
