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