test/built-ins/Array/prototype/lastIndexOf/15.4.4.15-2-6.js


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// Copyright (c) 2012 Ecma International.  All rights reserved.
// Ecma International makes this code available under the terms and conditions set
// forth on http://hg.ecmascript.org/tests/test262/raw-file/tip/LICENSE (the
// "Use Terms").   Any redistribution of this code must retain the above
// copyright and this notice and otherwise comply with the Use Terms.

/*---
es5id: 15.4.4.15-2-6
description: >
    Array.prototype.lastIndexOf - 'length' is an inherited data
    property on an Array-like object
includes: [runTestCase.js]
---*/

function testcase() {

        var proto = { length: 2 };

        var Con = function () {};
        Con.prototype = proto;

        var child = new Con();
        child[1] = "x";
        child[2] = "y";

        return Array.prototype.lastIndexOf.call(child, "x") === 1 &&
             Array.prototype.lastIndexOf.call(child, "y") === -1;
    }
runTestCase(testcase);