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 multiply = function (data, n, c) {
32 c2 += n * data[index];
33 data[index] = c2 % 1e7;
38 var divide = function (data, n) {
41 while (--index >= 0) {
43 data[index] = floor(c / n);
48 var dataToString = function (data) {
51 while (--index >= 0) {
52 if (s !== '' || index === 0 || data[index] !== 0) {
53 var t = String(data[index]);
54 s = s === '' ? t : s + repeat.call('0', 7 - t.length) + t;
59 var FORCED = nativeToFixed && (
60 0.00008.toFixed(3) !== '0.000' ||
61 0.9.toFixed(0) !== '1' ||
62 1.255.toFixed(2) !== '1.25' ||
63 1000000000000000128.0.toFixed(0) !== '1000000000000000128'
64 ) || !fails(function () {
66 nativeToFixed.call({});
69 // `Number.prototype.toFixed` method
70 // https://tc39.es/ecma262/#sec-number.prototype.tofixed
71 $({ target: 'Number', proto: true, forced: FORCED }, {
72 toFixed: function toFixed(fractionDigits) {
73 var number = thisNumberValue(this);
74 var fractDigits = toInteger(fractionDigits);
75 var data = [0, 0, 0, 0, 0, 0];
80 if (fractDigits < 0 || fractDigits > 20) throw RangeError('Incorrect fraction digits');
81 // eslint-disable-next-line no-self-compare -- NaN check
82 if (number != number) return 'NaN';
83 if (number <= -1e21 || number >= 1e21) return String(number);
89 e = log(number * pow(2, 69, 1)) - 69;
90 z = e < 0 ? number * pow(2, -e, 1) : number / pow(2, e, 1);
91 z *= 0x10000000000000;
97 multiply(data, 1e7, 0);
100 multiply(data, pow(10, j, 1), 0);
103 divide(data, 1 << 23);
106 divide(data, 1 << j);
107 multiply(data, 1, 1);
109 result = dataToString(data);
111 multiply(data, 0, z);
112 multiply(data, 1 << -e, 0);
113 result = dataToString(data) + repeat.call('0', fractDigits);
116 if (fractDigits > 0) {
118 result = sign + (k <= fractDigits
119 ? '0.' + repeat.call('0', fractDigits - k) + result
120 : result.slice(0, k - fractDigits) + '.' + result.slice(k - fractDigits));
122 result = sign + result;