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.
1 2 //+ Jonas Raoni Soares Silva 3 //@ http://jsfromhell.com/classes/bignumber [v1.0] 4 5 BigNumber = function(n, p, r){ 6 var o = this, i; 7 if(n instanceof BigNumber){ 8 for(i in {precision: 0, roundType: 0, _sign: 0, _dec: 0}) o[i] = n[i]; 9 o._buffer = n._buffer.slice(); 10 return; 11 } 12 o.precision = isNaN(p = Math.abs(p)) ? BigNumber.defaultPrecision : p; 13 o.roundType = isNaN(r = Math.abs(r)) ? BigNumber.defaultRoundType : r; 14 o._sign = (n += "").charAt(0) == "-"; 15 o._dec = ((n = n.replace(/[^\d.]/g, "").split(".", 2))[0] = n[0].replace(/^0+/, "") || "0").length; 16 for(i = (n = o._buffer = (n.join("") || "0").split("")).length; i; n[--i] = +n[i]); 17 o.round(); 18 }; 19 with({$: BigNumber, o: BigNumber.prototype}){ 20 $.ROUND_HALF_EVEN = ($.ROUND_HALF_DOWN = ($.ROUND_HALF_UP = ($.ROUND_FLOOR = ($.ROUND_CEIL = ($.ROUND_DOWN = ($.ROUND_UP = 0) + 1) + 1) + 1) + 1) + 1) + 1; 21 $.defaultPrecision = 40; 22 $.defaultRoundType = $.ROUND_HALF_UP; 23 o.add = function(n){ 24 if(this._sign != (n = new BigNumber(n))._sign) return n._sign = !n._sign, this.subtract(n); 25 var o = new BigNumber(this), a = o._buffer, b = n._buffer, la = o._dec, 26 lb = n._dec, n = Math.max(la, lb), i, r; 27 la != lb && ((lb = la - lb) > 0 ? o._zeroes(b, lb, 1) : o._zeroes(a, -lb, 1)); 28 i = (la = a.length) == (lb = b.length) ? a.length : ((lb = la - lb) > 0 ? o._zeroes(b, lb) : o._zeroes(a, -lb)).length; 29 for(r = 0; i; r = (a[--i] = a[i] + b[i] + r) / 10 >>> 0, a[i] %= 10); 30 return r && ++n && a.unshift(r), o._dec = n, o.round(); 31 }; 32 o.subtract = function(n){ 33 if(this._sign != (n = new BigNumber(n))._sign) return n._sign = !n._sign, this.add(n); 34 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; 35 a = a._buffer, b = b._buffer, la != lb && ((lb = la - lb) > 0 ? o._zeroes(b, lb, 1) : o._zeroes(a, -lb, 1)); 36 for(i = (la = a.length) == (lb = b.length) ? a.length : ((lb = la - lb) > 0 ? o._zeroes(b, lb) : o._zeroes(a, -lb)).length; i;){ 37 if(a[--i] < b[i]){ 38 for(j = i; j && !a[--j]; a[j] = 9); 39 --a[j], a[i] += 10; 40 } 41 b[i] = a[i] - b[i]; 42 } 43 return o._sign = !x, o._dec = n, o._buffer = b, o.round(); 44 }; 45 o.multiply = function(n){ 46 var o = new BigNumber(this), r = o.compare(n = new BigNumber(n)) + 1, a = (r ? o : n)._buffer, 47 b = (r ? n : o)._buffer, la = a.length, lb = b.length, x = new BigNumber, i, j, s; 48 for(i = lb; i; x.set(x.add(new BigNumber(s.join(""))))) 49 for(s = (new Array(lb - --i)).join("0").split(""), r = 0, j = la; j; 50 r += a[--j] * b[i], s.unshift(r % 10), r = r / 10 >>> 0); 51 return r && x._buffer.unshift(r), o._dec = (o._buffer = x._buffer).length - la - lb + o._dec + n._dec, o.round(); 52 }; 53 o.divide = function(n){ 54 if((n = new BigNumber(n)) == "0") throw new Error("division by 0"); 55 var o = new BigNumber(this), a = o._buffer, b = n._buffer, la = a.length - o._dec, 56 lb = b.length - n._dec, s = a._sign != b._sign, dec = 0, buffer = [], x = new BigNumber, y, i; 57 la != lb && ((lb = la - lb) > 0 ? o._zeroes(b, lb) : o._zeroes(a, -lb)); 58 o._dec = a.length, n._dec = b.length; 59 b = n, a._sign = false, b._sign = false; 60 while(o != 0 && (buffer.length - dec) <= o.precision){ 61 x.set(0); 62 for(i = 0; o.compare(y = x.add(b)) + 1 && ++i; x.set(y)); 63 if(!i){ 64 do ++i, o._buffer.push(0), ++o._dec; 65 while(o.compare(b) < 0); 66 !dec && (!buffer.length && buffer.push(0), dec = buffer.length); 67 o._zeroes(buffer, --i); 68 continue; 69 } 70 o.set(o.subtract(x)), buffer.push(i); 71 } 72 return o._buffer = buffer, o._dec = dec ? dec : buffer.length, o.round(); 73 }; 74 o.mod = function(n){ 75 return this.subtract(this.divide(n).intPart().multiply(n)); 76 }; 77 o.pow = function(n){ 78 var o = new BigNumber(this), i; 79 if(n == 0) return o.set(1); 80 for(i = Math.abs(n); --i; o.set(o.multiply(this))); 81 return n < 0 ? o.set((new BigNumber(1)).divide(o)) : o; 82 }; 83 o.set = function(n){ 84 return this.constructor(n), this; 85 }; 86 o.compare = function(n){ 87 var a = this, la = this._dec, b = n, lb = n._dec, i, l; 88 if(la != lb) return la > lb ? 1 : -1; 89 for(la = (a = a._buffer).length, lb = (b = b._buffer).length, i = -1, l = Math.min(la, lb); ++i < l;) 90 if(a[i] != b[i]) return a[i] > b[i] ? 1 : -1; 91 return la != lb ? la > lb ? 1 : -1 : 0; 92 } 93 o.negate = function(){ 94 var n = new BigNumber(this); return n._sign ^= 1, n; 95 }; 96 o.abs = function(){ 97 var n = new BigNumber(this); return n._sign = 0, n; 98 }; 99 o.intPart = function(){ 100 return new BigNumber((this._sign ? "-" : "") + (this._buffer.slice(0, this._dec).join("") || "0")); 101 }; 102 o.valueOf = o.toString = function(){ 103 var o = this; 104 return (o._sign ? "-" : "") + (o._buffer.slice(0, o._dec).join("") || "0") + (o._dec != o._buffer.length ? "." + o._buffer.slice(o._dec).join("") : ""); 105 }; 106 o._zeroes = function(n, l, t){ 107 var s = ["push", "unshift"][t || 0]; 108 for(++l; --l; n[s](0)); 109 return n; 110 }; 111 o.round = function(){ 112 if("_rounding" in this) return this; 113 var $ = BigNumber, r = this.roundType, b = this._buffer, d, p, n, x; 114 for(this._rounding = true; this._dec > 1 && !b[0]; --this._dec, b.shift()); 115 for(d = this._dec, p = this.precision + d, n = b[p]; b.length > d && !b[b.length -1]; b.pop()); 116 x = (this._sign ? "-" : "") + (p - d ? "0." + this._zeroes([], p - d - 1).join("") : "") + 1; 117 if(b.length > p){ 118 n && (r == $.DOWN ? false : r == $.UP ? true : r == $.CEIL ? !this._sign 119 : r == $.FLOOR ? this._sign : r == $.HALF_UP ? n >= 5 : r == $.HALF_DOWN ? n > 5 120 : r == $.HALF_EVEN ? n >= 5 && b[p - 1] & 1 : false) && this.add(x); 121 b.splice(p, b.length - p); 122 } 123 return delete this._rounding, this; 124 }; 125 }
Usage
1 2 <script type="text/javascript"> 3 4 var x = new BigNumber("10"), y = new BigNumber("-2"); 5 alert(x.pow(y)); 6 alert(x.pow(1234)); 7 8 alert((new BigNumber("99999999999999999999999999999999999")).add("999999999999999999999999999.99999999999999999")); 9 10 </script>
