2 var $ = require('../internals/export');
3 var toInteger = require('../internals/to-integer');
4 var parseInt = require('../internals/number-parse-int');
6 var INVALID_NUMBER_REPRESENTATION = 'Invalid number representation';
7 var INVALID_RADIX = 'Invalid radix';
8 var valid = /^[\da-z]+$/;
10 // `Number.fromString` method
11 // https://github.com/tc39/proposal-number-fromstring
12 $({ target: 'Number', stat: true }, {
13 fromString: function fromString(string, radix) {
16 if (typeof string != 'string') throw TypeError(INVALID_NUMBER_REPRESENTATION);
17 if (!string.length) throw SyntaxError(INVALID_NUMBER_REPRESENTATION);
18 if (string.charAt(0) == '-') {
20 string = string.slice(1);
21 if (!string.length) throw SyntaxError(INVALID_NUMBER_REPRESENTATION);
23 R = radix === undefined ? 10 : toInteger(radix);
24 if (R < 2 || R > 36) throw RangeError(INVALID_RADIX);
25 if (!valid.test(string) || (mathNum = parseInt(string, R)).toString(R) !== string) {
26 throw SyntaxError(INVALID_NUMBER_REPRESENTATION);
28 return sign * mathNum;