1// Copyright 2010 the V8 project authors. All rights reserved.
2// Redistribution and use in source and binary forms, with or without
3// modification, are permitted provided that the following conditions are
4// met:
5//
6//     * Redistributions of source code must retain the above copyright
7//       notice, this list of conditions and the following disclaimer.
8//     * Redistributions in binary form must reproduce the above
9//       copyright notice, this list of conditions and the following
10//       disclaimer in the documentation and/or other materials provided
11//       with the distribution.
12//     * Neither the name of Google Inc. nor the names of its
13//       contributors may be used to endorse or promote products derived
14//       from this software without specific prior written permission.
15//
16// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27
28function IsNull(x) {
29  if (x == null) return true; else return false;
30}
31
32assertTrue(IsNull(null), "null == null");
33assertTrue(IsNull(void 0), "void 0 == null");
34assertFalse(IsNull(42), "42 != null");
35
36
37function IsNullStrict(x) {
38  if (x === null) return true; else return false;
39}
40
41assertTrue(IsNullStrict(null), "null === null");
42assertFalse(IsNullStrict(void 0), "void 0 != null");
43assertFalse(IsNullStrict(87), "87 !== null");
44
45
46function GimmeFalse(x) {
47  if ((x & 1) == null) return true;
48  if ((x | 3) === null) return true;
49  return false;
50}
51
52assertFalse(GimmeFalse(1), "GimmeFalse(1)");
53assertFalse(GimmeFalse(null), "GimmeFalse(null)");
54assertFalse(GimmeFalse({}), "GimmeFalse({})");
55