es6.string.starts-with.js

// 21.1.3.18 String.prototype.startsWith(searchString [, position ])
'use strict';
var $export = require('./_export');
var toLength = require('./_to-length');
var context = require('./_string-context');
var STARTS_WITH = 'startsWith';
var $startsWith = ''[STARTS_WITH];

$export($export.P + $export.F * require('./_fails-is-regexp')(STARTS_WITH), 'String', {
  startsWith: function startsWith(searchString /* , position = 0 */) {
    var that = context(this, searchString, STARTS_WITH);
    var index = toLength(Math.min(arguments.length > 1 ? arguments[1] : undefined, that.length));
    var search = String(searchString);
    return $startsWith
      ? $startsWith.call(that, search, index)
      : that.slice(index, index + search.length) === search;
  }
});