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

sdk/lib/io/http_utils.dart

 // Copyright (c) 2012, 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.
 
 class _HttpUtils {
   static String decodeUrlEncodedString(String urlEncoded) {
     // First check the string for any encoding.
     int index = 0;
     bool encoded = false;
     while (!encoded && index < urlEncoded.length) {
@@ skipping 244 matching lines @@
     void error() {
       throw new HttpException("Invalid cookie date $date");
     }
 
     bool isEnd() {
       return position == date.length;
     }
 
     bool isDelimiter(String s) {
       int char = s.charCodeAt(0);
-      if (char === 0x09) return true;
+      if (char == 0x09) return true;
       if (char >= 0x20 && char <= 0x2F) return true;
       if (char >= 0x3B && char <= 0x40) return true;
       if (char >= 0x5B && char <= 0x60) return true;
       if (char >= 0x7B && char <= 0x7E) return true;
       return false;
     }
 
     bool isNonDelimiter(String s) {
       int char = s.charCodeAt(0);
       if (char >= 0x00 && char <= 0x08) return true;
@@ skipping 32 matching lines @@
       while (!isEnd() && isDelimiter(date[position])) position++;
     }
 
     String timeStr;
     String dayOfMonthStr;
     String monthStr;
     String yearStr;
 
     for (var token in tokens) {
       if (token.length < 1) continue;
-      if (timeStr === null && token.length >= 5 && isDigit(token[0]) &&
+      if (timeStr == null && token.length >= 5 && isDigit(token[0]) &&
           (token[1] == ":" || (isDigit(token[1]) && token[2] == ":"))) {
         timeStr = token;
-      } else if (dayOfMonthStr === null && isDigit(token[0])) {
+      } else if (dayOfMonthStr == null && isDigit(token[0])) {
         dayOfMonthStr = token;
-      } else if (monthStr === null && getMonth(token) >= 0) {
+      } else if (monthStr == null && getMonth(token) >= 0) {
         monthStr = token;
-      } else if (yearStr === null && token.length >= 2 &&
+      } else if (yearStr == null && token.length >= 2 &&
                  isDigit(token[0]) && isDigit(token[1])) {
         yearStr = token;
       }
     }
 
-    if (timeStr === null || dayOfMonthStr === null ||
-        monthStr === null || yearStr === null) {
+    if (timeStr == null || dayOfMonthStr == null ||
+        monthStr == null || yearStr == null) {
       error();
     }
 
     int year = toInt(yearStr);
     if (year >= 70 && year <= 99) year += 1900;
     else if (year >= 0 && year <= 69) year += 2000;
     if (year < 1601) error();
 
     int dayOfMonth = toInt(dayOfMonthStr);
     if (dayOfMonth < 1 || dayOfMonth > 31) error();
 
     int month = getMonth(monthStr) + 1;
 
     var timeList = timeStr.split(":");
-    if (timeList.length !== 3) error();
+    if (timeList.length != 3) error();
     int hour = toInt(timeList[0]);
     int minute = toInt(timeList[1]);
     int second = toInt(timeList[2]);
     if (hour > 23) error();
     if (minute > 59) error();
     if (second > 59) error();
 
     return new Date.utc(year, month, dayOfMonth, hour, minute, second, 0);
   }
 }