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 [rev. #3] 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) 25 return n._sign ^= 1, this.subtract(n); 26 var o = new BigNumber(this), a = o._buffer, b = n._buffer, la = o._dec, 27 lb = n._dec, n = Math.max(la, lb), i, r; 28 la != lb && ((lb = la - lb) > 0 ? o._zeroes(b, lb, 1) : o._zeroes(a, -lb, 1)); 29 i = (la = a.length) == (lb = b.length) ? a.length : ((lb = la - lb) > 0 ? o._zeroes(b, lb) : o._zeroes(a, -lb)).length; 30 for(r = 0; i; r = (a[--i] = a[i] + b[i] + r) / 10 >>> 0, a[i] %= 10); 31 return r && ++n && a.unshift(r), o._dec = n, o.round(); 32 }; 33 o.subtract = function(n){ 34 if(this._sign != (n = new BigNumber(n))._sign) 35 return n._sign ^= 1, this.add(n); 36 var o = new BigNumber(this), c = o.abs().compare(n.abs()) + 1, a = c ? o : n, b = c ? n : o, la = a._dec, lb = b._dec, d = la, i, j; 37 a = a._buffer, b = b._buffer, la != lb && ((lb = la - lb) > 0 ? o._zeroes(b, lb, 1) : o._zeroes(a, -lb, 1)); 38 for(i = (la = a.length) == (lb = b.length) ? a.length : ((lb = la - lb) > 0 ? o._zeroes(b, lb) : o._zeroes(a, -lb)).length; i;){ 39 if(a[--i] < b[i]){ 40 for(j = i; j && !a[--j]; a[j] = 9); 41 --a[j], a[i] += 10; 42 } 43 b[i] = a[i] - b[i]; 44 } 45 return c || (o._sign = n._sign), o._dec = d, o._buffer = b, o.round(); 46 }; 47 o.multiply = function(n){ 48 var o = new BigNumber(this), r = o._buffer.length >= (n = new BigNumber(n))._buffer.length, a = (r ? o : n)._buffer, 49 b = (r ? n : o)._buffer, la = a.length, lb = b.length, x = new BigNumber, i, j, s; 50 for(i = lb; i; r && s.unshift(r), x.set(x.add(new BigNumber(s.join(""))))) 51 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); 52 return o._dec = ((r = la + lb - o._dec - n._dec) >= (j = (o._buffer = x._buffer).length) ? this._zeroes(o._buffer, r - j + 1, 1).length : j) - r, o.round(); 53 }; 54 o.divide = function(n){ 55 if((n = new BigNumber(n)) == "0") 56 throw new Error("Division by 0"); 57 else if(this == "0") 58 return new BigNumber; 59 var o = new BigNumber(this), a = o._buffer, b = n._buffer, la = a.length - o._dec, 60 lb = b.length - n._dec, r = new BigNumber, i = 0, j, s, last; 61 r._sign = o._sign != n._sign, r.precision = Math.max(o.precision, n.precision), 62 r._dec = +r._buffer.pop(), la != lb && o._zeroes(la > lb ? b : a, Math.abs(la - lb)); 63 n._dec = b.length, b = n, b._sign = false, b = b.round(); 64 for(n = new BigNumber; a[0] == "0"; a.shift()); 65 out: 66 do{ 67 for(n == "0" && (n._buffer = [], n._dec = 0), last = 0; i < a.length && n.compare(b) == -1; ++i){ 68 if(last = i + 1 == a.length, n == "0" && a[i] == "0"){ 69 if(r._dec == r._buffer.length && ++r._dec, r._buffer.push(0), last) 70 break out; 71 } 72 else if(n._buffer.push(a[i]), ++n._dec, (last && n.compare(b) == -1 && (r._dec == r._buffer.length && ++r._dec, 1)) || (last = 0)) 73 do 74 r._buffer.push(0), n._buffer.push(0), ++n._dec; 75 while(n.compare(b) == -1); 76 } 77 if(n.compare(b) == -1 && !(last = 0)) 78 do 79 last ? r._buffer.push(0) : last = 1, n._buffer.push(0), ++n._dec; 80 while(n.compare(b) == -1); 81 for(s = new BigNumber, j = 0; n.compare(y = s.add(b)) + 1 && ++j; s.set(y)); 82 n.set(n.subtract(s)), !last && r._dec == r._buffer.length && ++r._dec, r._buffer.push(j); 83 } 84 while((i < a.length || n != "0") && (r._buffer.length - r._dec) <= r.precision); 85 return r.round(); 86 }; 87 o.mod = function(n){ 88 return this.subtract(this.divide(n).intPart().multiply(n)); 89 }; 90 o.pow = function(n){ 91 var o = new BigNumber(this), i; 92 if((n = (new BigNumber(n)).intPart()) == 0) return o.set(1); 93 for(i = Math.abs(n); --i; o.set(o.multiply(this))); 94 return n < 0 ? o.set((new BigNumber(1)).divide(o)) : o; 95 }; 96 o.set = function(n){ 97 return this.constructor(n), this; 98 }; 99 o.compare = function(n){ 100 var a = this, la = this._dec, b = new BigNumber(n), lb = b._dec, r = [-1, 1], i, l; 101 if(a._sign != b._sign) 102 return a._sign ? -1 : 1; 103 if(la != lb) 104 return r[(la > lb) ^ a._sign]; 105 for(la = (a = a._buffer).length, lb = (b = b._buffer).length, i = -1, l = Math.min(la, lb); ++i < l;) 106 if(a[i] != b[i]) 107 return r[(a[i] > b[i]) ^ a._sign]; 108 return la != lb ? r[(la > lb) ^ a._sign] : 0; 109 }; 110 o.negate = function(){ 111 var n = new BigNumber(this); return n._sign ^= 1, n; 112 }; 113 o.abs = function(){ 114 var n = new BigNumber(this); return n._sign = 0, n; 115 }; 116 o.intPart = function(){ 117 return new BigNumber((this._sign ? "-" : "") + (this._buffer.slice(0, this._dec).join("") || "0")); 118 }; 119 o.valueOf = o.toString = function(){ 120 var o = this; 121 return (o._sign ? "-" : "") + (o._buffer.slice(0, o._dec).join("") || "0") + (o._dec != o._buffer.length ? "." + o._buffer.slice(o._dec).join("") : ""); 122 }; 123 o._zeroes = function(n, l, t){ 124 var s = ["push", "unshift"][t || 0]; 125 for(++l; --l; n[s](0)); 126 return n; 127 }; 128 o.round = function(){ 129 if("_rounding" in this) return this; 130 var $ = BigNumber, r = this.roundType, b = this._buffer, d, p, n, x; 131 for(this._rounding = true; this._dec > 1 && !b[0]; --this._dec, b.shift()); 132 for(d = this._dec, p = this.precision + d, n = b[p]; b.length > d && !b[b.length -1]; b.pop()); 133 x = (this._sign ? "-" : "") + (p - d ? "0." + this._zeroes([], p - d - 1).join("") : "") + 1; 134 if(b.length > p){ 135 n && (r == $.DOWN ? false : r == $.UP ? true : r == $.CEIL ? !this._sign 136 : r == $.FLOOR ? this._sign : r == $.HALF_UP ? n >= 5 : r == $.HALF_DOWN ? n > 5 137 : r == $.HALF_EVEN ? n >= 5 && b[p - 1] & 1 : false) && this.add(x); 138 b.splice(p, b.length - p); 139 } 140 return delete this._rounding, this; 141 }; 142 }
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>
