You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
27 lines
980 B
27 lines
980 B
11 months ago
|
'use strict';
|
||
|
|
var $ = require('../internals/export');
|
||
|
|
var uncurryThis = require('../internals/function-uncurry-this');
|
||
|
|
var requireObjectCoercible = require('../internals/require-object-coercible');
|
||
|
|
var toIntegerOrInfinity = require('../internals/to-integer-or-infinity');
|
||
|
|
var toString = require('../internals/to-string');
|
||
|
|
var fails = require('../internals/fails');
|
||
|
|
|
||
|
|
var charAt = uncurryThis(''.charAt);
|
||
|
|
|
||
|
|
var FORCED = fails(function () {
|
||
|
|
// eslint-disable-next-line es/no-array-string-prototype-at -- safe
|
||
|
|
return '𠮷'.at(-2) !== '\uD842';
|
||
|
|
});
|
||
|
|
|
||
|
|
// `String.prototype.at` method
|
||
|
|
// https://tc39.es/ecma262/#sec-string.prototype.at
|
||
|
|
$({ target: 'String', proto: true, forced: FORCED }, {
|
||
|
|
at: function at(index) {
|
||
|
|
var S = toString(requireObjectCoercible(this));
|
||
|
|
var len = S.length;
|
||
|
|
var relativeIndex = toIntegerOrInfinity(index);
|
||
|
|
var k = relativeIndex >= 0 ? relativeIndex : len + relativeIndex;
|
||
|
|
return (k < 0 || k >= len) ? undefined : charAt(S, k);
|
||
|
|
}
|
||
|
|
});
|