2 var $ = require('../internals/export');
3 var toInteger = require('../internals/to-integer');
4 var thisNumberValue = require('../internals/this-number-value');
5 var repeat = require('../internals/string-repeat');
6 var fails = require('../internals/fails');
8 var nativeToFixed = 1.0.toFixed;
9 var floor = Math.floor;
11 var pow = function (x, n, acc) {
12 return n === 0 ? acc : n % 2 === 1 ? pow(x, n - 1, acc * x) : pow(x * x, n / 2, acc);
15 var log = function (x) {
28 var FORCED = nativeToFixed && (
29 0.00008.toFixed(3) !== '0.000' ||
30 0.9.toFixed(0) !== '1' ||
31 1.255.toFixed(2) !== '1.25' ||
32 1000000000000000128.0.toFixed(0) !== '1000000000000000128'
33 ) || !fails(function () {
35 nativeToFixed.call({});
38 // `Number.prototype.toFixed` method
39 // https://tc39.github.io/ecma262/#sec-number.prototype.tofixed
40 $({ target: 'Number', proto: true, forced: FORCED }, {
41 // eslint-disable-next-line max-statements
42 toFixed: function toFixed(fractionDigits) {
43 var number = thisNumberValue(this);
44 var fractDigits = toInteger(fractionDigits);
45 var data = [0, 0, 0, 0, 0, 0];
50 var multiply = function (n, c) {
54 c2 += n * data[index];
55 data[index] = c2 % 1e7;
60 var divide = function (n) {
63 while (--index >= 0) {
65 data[index] = floor(c / n);
70 var dataToString = function () {
73 while (--index >= 0) {
74 if (s !== '' || index === 0 || data[index] !== 0) {
75 var t = String(data[index]);
76 s = s === '' ? t : s + repeat.call('0', 7 - t.length) + t;
81 if (fractDigits < 0 || fractDigits > 20) throw RangeError('Incorrect fraction digits');
82 // eslint-disable-next-line no-self-compare
83 if (number != number) return 'NaN';
84 if (number <= -1e21 || number >= 1e21) return String(number);
90 e = log(number * pow(2, 69, 1)) - 69;
91 z = e < 0 ? number * pow(2, -e, 1) : number / pow(2, e, 1);
92 z *= 0x10000000000000;
101 multiply(pow(10, j, 1), 0);
110 result = dataToString();
113 multiply(1 << -e, 0);
114 result = dataToString() + repeat.call('0', fractDigits);
117 if (fractDigits > 0) {
119 result = sign + (k <= fractDigits
120 ? '0.' + repeat.call('0', fractDigits - k) + result
121 : result.slice(0, k - fractDigits) + '.' + result.slice(k - fractDigits));
123 result = sign + result;