a === b -> identical(a, b)

tests/language/comparison_test.dart

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 // Dart test program for testing comparison operators.
 
 class Helper {
   static bool STRICT_EQ(a, b) {
-    return a === b;
+    return identical(a, b);
   }
 
   static bool STRICT_NE(a, b) {
-    return a !== b;
+    return !identical(a, b);
   }
 
   static bool EQ(a, b) {
     return a == b;
   }
 
   static bool NE(a, b) {
     return a != b;
   }
 
@@ skipping 268 matching lines @@
     Expect.equals(false, Helper.LT(1.2, 1.1));
     Expect.equals(false, Helper.LT(1.2, 1.1));
     Expect.equals(false, Helper.LT(1.2, 1.1));
 
     Expect.equals(false, Helper.GE(1.1, 1.2));
     Expect.equals(false, Helper.GE(1.1, 1.2));
     Expect.equals(true, Helper.GE(1.2, 1.2));
     Expect.equals(true, Helper.GE(1.2, 1.2));
 
     // With non-number classes.
     Expect.equals(false, Helper.EQ(1, "eeny"));

[Lasse Reichstein Nielsen, 2012/11/12 13:10:41]

Expect.isFalse

[floitsch, 2012/11/12 22:18:43]

Done.

     Expect.equals(false, Helper.EQ("meeny", 1));
     Expect.equals(false, Helper.EQ(1.1, "miny"));
     Expect.equals(false, Helper.EQ("moe", 1.1));
     Expect.equals(false, Helper.EQ(1.1, "catch"));
     Expect.equals(false, Helper.EQ("the", 1.1));
 
     // With null.
     Expect.equals(false, Helper.EQ(1, null));
     Expect.equals(false, Helper.EQ(null, 1));
     Expect.equals(false, Helper.EQ(1.1, null));
     Expect.equals(false, Helper.EQ(null, 1.1));
     Expect.equals(false, Helper.EQ(1.1, null));
     Expect.equals(false, Helper.EQ(null, 1.1));
 
     // TODO(srdjan): Clarify behaviour of greater/less comparisons
     // between numbers and non-numbers.
   }
 }
 
 main() {
   ComparisonTest.testMain();
 }