Finding the number of common elements between two arrays
Get different and common items in two arrays with LINQ
What does a "CALLBACK" declaration in C do? I was looking through some code from the  library and came across a function declared like this:  LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)   Now, I'm a Delphi coder.  No hablo C muy bien, senor.  But I remember enough syntax from my college courses to read it like this:  Function name is WndProc.  Argument list is pretty self-explanatory.  Function return type is LRESULT.  But what in the world is that "CALLBACK" doing there?  In Delphi, any function can be used as a callback; you just need to pass the right type of function pointer.  Is there any particular reason why C doesn't work that way?  Or does it mean something different? I am a little at a loss.  A couple years before my mother-in-law passed away she signed her house over to my wife and her sister via a quitclaim deed.    After she passed we sold the house for $80,000. The money was used to pay off the mortgage, some other funeral expenses, and sent $15,000 to other family members.  All the money was dispersed at the closing of the house.  My wife and her sister each ended up with about $20,000.  How do we go about claiming this income?  Since there was a quitclaim deed I guess we technically owned the house for a few years prior to its sale.  How does that affect our tax and what is the basis?  Is the basis the selling price(fair market value) or something else?  How much does each sister claim for gains?  Sorry it this is a jumble of questions I am just trying to get this straightened out before tax is due. As made clear in update 3 on , this notation: var hash = {}; hash[X]  does not actually hash the object X; it actually just converts X to a string (via .toString() if it's an object, or some other built-in conversions for various primitive types) and then looks that string up, without hashing it, in &quot;hash&quot;. Object equality is also not checked - if two different objects have the same string conversion, they will just overwrite each other. Given this - are there any efficient implementations of hashmaps in JavaScript? (For example, the second Google result of  yields an implementation which is O(n) for any operation. Various other results ignore the fact that different objects with equivalent string representations overwrite each other. How to install XAMPP? Why is the direction of cross products of two vectors perpendicular to the plane? Why is the direction of cross products of two vectors perpendicular to the plane? How is that possible? How to place a float at the top of a floats-only page? I just got a short algorithm on my page, and it keeps getting aligned at the center of the page. But I want to have it aligned at the top, what do I have to do? I  want to download free app in my iPod touch device and i have the following doubts.  Kindly resolve me doubts.   when i try to download it asks my credit card security number. since i am trying to download free app , why do i need to provide my credit card security code? Will i be debited for downloading the free app from app store?   I cant able to find any information regarding this on apple.  Please provide me some references about this from apple and please resolve my doubts.  Thanks a lot. sed : Ignore line starting whitespace for match I want to replace the default listening port of httpd to 9090. I can edit the line in httpd.conf file using below  sed -i "/^Listen/c\Listen 9090" /etc/httpd/conf/httpd.conf   But the line   Listen 80   may have white space before it.  How do I ignore this white space to match this line? Android popup window dismissal I have installed Linux Bash on Windows 10 (available from Microsoft), but I've forgotten my password.  I've searched for a solution but I only find suggestions that involve doing something before the system boots, like accessing recovery mode, but that will not work in this case as this Ubuntu is just an application within a Windows system and doesn't have its own boot process.  How can I reset my password? I don't know the command to set our spawn in Minecraft 1.12.1.  Is it /set spawn? I honestly can't figure it out. Thanks! How to run Java code using Java code? How can one prove that numbers of the form $4x^2+1$ can only be divided by primes of the form $4y+1$ (e.g. there is no $x$ for which $7$ divides $4x^2+1$)?   On a quick lookup, the statement is given as the first comment in  and of course, manual testing concurs with this Do virtual particles actually physically exist? I have heard  pop in and out of existence all the time, most notable being the pairs that pop out beside black holes and while one gets pulled away. But wouldn't this actually violate the conservation of energy? I want to display from cache for a long time and I want a slightly different behavior on page render vs loading the page from cache.  Is there an easy way I can determine this with JavaScript? Why are two different concepts both called "heap"? Shiny locked Legendaries in ORAS Serebii says that (probably) the only  in ORAS are Kyogre, Groudon, Rayquaza and Deoxys. This means that Reshiram and Zekrom, that were shiny locked in BW/B2W2, now can be found shiny.    Can anyone prove this? I'd like to know if it's true before waste hours in softresetting. Can I have 2x2 workspaces in GNOME 3? Not able to understand the meaning of question? car moving with a speed of 40 km / h can be stopped by applying brakes after at least 2 m. If the same car is moving with a speed of 80 km / h, what is the minimum stopping distance  Does this mean that after 2 m, You will apply brakes and then it stops. What is the retardation value  with which you are brakes.I am not understand the meaning of the values. Why doesn't an Environment texture appear when the world has a Volume Scatter shader? I'm working on lighting a scene in which I need to have both an Environment texture for the background and Volume Scatter for light cones, but when I check the volume section in World setting and choose the Volume Scatter, the environment becomes black background (but the lighting works as I want).  I'm using Blender 2.72  How can this be fixed?