// Copyright (c) 2012 Ecma International. All rights reserved. // This code is governed by the BSD license found in the LICENSE file. /*--- esid: sec-array.prototype.lastindexof description: > Array.prototype.lastIndexOf returns -1 if 'length' is 0 (length is an empty array) ---*/ // objects inherit the default valueOf method of the Object object; // that simply returns the itself. Since the default valueOf() method // does not return a primitive value, ES next tries to convert the object // to a number by calling its toString() method and converting the // resulting string to a number. // // The toString( ) method on Array converts the array elements to strings, // then returns the result of concatenating these strings, with commas in // between. An array with no elements converts to the empty string, which // converts to the number 0. If an array has a single element that is a // number n, the array converts to a string representation of n, which is // then converted back to n itself. If an array contains more than one element, // or if its one element is not a number, the array converts to NaN. var i = Array.prototype.lastIndexOf.call({ length: [] }, 1); assert.sameValue(i, -1, 'i'); reportCompare(0, 0);