to-index.js
457 Bytes
var toIntegerOrInfinity = require('../internals/to-integer-or-infinity');
var toLength = require('../internals/to-length');
var $RangeError = RangeError;
// `ToIndex` abstract operation
// https://tc39.es/ecma262/#sec-toindex
module.exports = function (it) {
if (it === undefined) return 0;
var number = toIntegerOrInfinity(it);
var length = toLength(number);
if (number !== length) throw $RangeError('Wrong length or index');
return length;
};