JSTests/test262/test/built-ins/Array/prototype/filter/15.4.4.20-9-b-1.js

// 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.filter
es5id: 15.4.4.20-9-b-1
description: >
    Array.prototype.filter - callbackfn not called for indexes never
    been assigned values
---*/

  var callCnt = 0;
  function callbackfn(val, idx, obj)
  {
    callCnt++;
    return false;
  }

  var srcArr = new Array(10);
  srcArr[1] = undefined; //explicitly assigning a value
  var resArr = srcArr.filter(callbackfn);

assert.sameValue(resArr.length, 0, 'resArr.length');
assert.sameValue(callCnt, 1, 'callCnt');