1 // TODO: disabled by default because of the conflict with another proposal
3 var $ = require('../internals/export');
4 var requireObjectCoercible = require('../internals/require-object-coercible');
5 var toLength = require('../internals/to-length');
6 var toInteger = require('../internals/to-integer');
7 var fails = require('../internals/fails');
9 var FORCED = fails(function () {
10 return '𠮷'.at(0) !== '\uD842';
13 // `String.prototype.at` method
14 // https://github.com/tc39/proposal-relative-indexing-method
15 $({ target: 'String', proto: true, forced: FORCED }, {
16 at: function at(index) {
17 var S = String(requireObjectCoercible(this));
18 var len = toLength(S.length);
19 var relativeIndex = toInteger(index);
20 var k = relativeIndex >= 0 ? relativeIndex : len + relativeIndex;
21 return (k < 0 || k >= len) ? undefined : S.charAt(k);