As the question says, what exactly is the function of the !== operator? (Exclaimation, Equals, Equals).  Yes there are two equal signs. I found it .   function endsWith(str, suffix) {      return str.indexOf(suffix, str.length - suffix.length) !== -1;   }    Is it a typo? I doubt it. It is an old post and with so many upvotes, it should surely have been corrected one day or the other.  Or is it a valid operator? If so, what does it do?
I'm using  to go through JavaScript, and it's returning many suggestions to replace == (two equals signs) with === (three equals signs) when doing things like comparing idSele_UNVEHtype.value.length == 0 inside of an if statement.  Is there a performance benefit to replacing == with ===?   Any performance improvement would be welcomed as many comparison operators exist.  If no type conversion takes place, would there be a performance gain over ==?
What is a combo update and how is it different than the regular update? present continous or present perfect continous? Should I write 'I have been reading a book now' or 'I am reading a book now'? I started to read one week ago and I haven't ended yet. Thanks for help For macro photography, how do I choose between a compact camera or a mirrorless interchangeable-lens camera (without considering a lens)?   What indicator(s) should I look for when making the choice? Combining php arrays I have the following arrays in PHP (okay they are a bit bigger but the idea is what counts).  $array1 = array(1 =&gt; 'a', 2 =&gt; 'b'); $array2 = array(3 =&gt; 'c', 4 =&gt; 'd');   Essentially I want to combine the two arrays as if it were something like this  $array3 = array(1 =&gt; 'a', 2 =&gt; 'b', 3 =&gt; 'c', 4 =&gt; 'd');   Thanks What is the speed of time? Java is one of my programming languages of choice.  I always run into the problem though of distributing my application to end-users.  Giving a user a JAR is not always as user friendly as I would like and using Java WebStart requires that I maintain a web server.  What's the best way to distribute a Java application?  What if the Java application needs to install artifacts to the user's computer?  Are there any good Java installation/packaging systems out there? "Z-level" in TikZ Visualforce Date formatting So the problem is that account 1 and account 2 bought a game together, but account 1 isn't used anymore. Can we transfer the game license from account 1 to account 3?   The game was bought on account 1 and account 2 activated account 1 as primary. This seems to be a chicken-egg problem. The most common task using sudo is installing and removing software.  sudo apt-get purge &lt;appname&gt;   But sudo itself can be removed.  sudo apt-get purge sudo # Do not run this command on production computers!   This is where the fun comes  ubuntu@ubuntu:~$ sudo bash: /usr/bin/sudo: No such file or directory   Although it's obvious that no person in his right mind will purge sudo (other than me), someone can be fooled to run this command (not directly, in its hex mode, or whatever it's called) or a person could SSH in disguised as tech guru and do the mess.  So is there a way of reinstalling sudo? If derivative of function is less than or equal to 4, prove the existence of point $c$ so $f(c)=c^2$. I am struggling to construct a simple proof of the following.  Suppose $f(x)$ is differentiable for any real value $x$ and that $f'(x) \le 4$ for all real values of x. Prove there is at most one real value $c&gt;2$ such that $f(c) =c^2$.  I am completely lost on where to start on this proof and any help would be greatly appreciated! Actually I have installed the new Ubuntu 15.04 64bit, and when I'm trying to install Steam on it, there is a problem. In fact I have downloaded the deb package from steam website, installed it and when I start it nothing happens. I tried to start it from terminal and what I've got  $ steam Running Steam on ubuntu 15.04 64-bit STEAM_RUNTIME is enabled automatically Installing breakpad exception handler for appid(steam)/version(0_client) libGL error: unable to load driver: r600_dri.so libGL error: driver pointer missing libGL error: failed to load driver: r600 libGL error: unable to load driver: swrast_dri.so libGL error: failed to load driver: swrast “Are” vs. “is” after “parents and the family” Can I use a spell with a casting time of "Bonus Action" as my action? Should we improve time to first byte or Page Speed Insights score for SEO? Google posted last summer that "page speed" will impact the search result rankings also on mobile devices. But I think there is a little confusion about the term "page speed".  The test tool which Google offers is called "Page Speed Insights". Many people we are talking with, are thinking that the overall score of this tool for a particular site for example Desktop: 46/100 and Mobile: 45/100 is used for the ranking algorithm.  BUT I found a very interesting article in German language which states that only the TTFB (time to first byte) value is used and this should be optimized not all suggestions which "Page Speed Insights", further called PSI offers. Here is the link to the German article:   In short terms it says that a very large site in this case "The New York Times" has a low overall score of Mobile:41 and Desktop:45. As they are used to sell reader memberships they should  offer a great user experience. So, they should optimize their site. But when I call this site it is amazing fast. The overall PSI score does not reflect this behaviour. But when I believe this article the TTFB for this site is perfect. Also when I call it here from Austria it states 0.881sec.  I really like to know on which value we should focus our work for optimization not to fall in the ranking. Because as many of you already said it is not useful to implement all suggestions from the PSI site for one domain.  So, it would be real  if you could clarify things here or post links to official posts from Google. What I found about this, Google always is talking about "page speed" but what exactly is this? Blank questions and answers I have white blank on the posts.    App Version: 1.0.89 Device Manufacturer: Meizu Device Model: m2   OS Version: 5.1 (1464689330)    I can't see the questions and the answers and the comments.  I saw that it's a common issue..  Does it have a fix?   EDIT -  I saw  answer. This answer is ~2 years old. It says that it will fix in the next update.  His version is 1.0.59 - mine is 1.0.89. Huge different.   The problem is still exists! Continuity $\Rightarrow$ Intermediate Value Property. Why is the opposite not true?    It seems to me like they are equal definitions in a way.    Can you give me a counter-example?    Thanks Call C++ library in C# I have a lot of libraries written in C++. I want to call these libraries from C#, however, I have met many problems. I want to know if there is a book or guideline to tell me how to do that. Can I have multiple Schengen visas for future travels in my passport? I'm a citizen of Ukraine planning on visiting Italy early in October for tourism. Later that month I'm accepted as a speaker at the conference in Prague, Czech Republic. Both countries are members of Schengen agreement and a visa is required for me to visit them. Therefore, I need to visit Schengen countries 2 times and I need to get my visas ASAP (to confirm my talk to the conference organizers, as well as to avoid overpaying for hotels/flight tickets).   I've heard a number of times that a single person can't apply for a Schengen visa if already in possession of one, but I'd like to clarify this. Say, I've got a visa from Italy for the period of October 1st - October 14th. Can I get another one from Czech Republic for October 25th - October 30th before I visit Italy? Would the answer be different if I were to visit the second country (CZ) on October 13th - October 20th, thus, having a single day overlap between these visits. It would be of a tremendous help if you could link to the official documents that prove your point, but I'd certainly appreciate answers even without such links.  Both times I'm going to apply for a short-term tourist visa covering the dates of my travel. If the answer to both questions above is no - would several visits to multiple Schengen countries over a short period of time be a valid reason to apply for a single multiple-entry visa that covers the whole period from October 1st to October 30th from Italy? Examples of infinite groups such that all their respective elements are of finite order. I am in need of examples of infinite groups such that all their respective elements are of finite order.