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18
votes2
answers5391
viewsWhat is the HMAC?
When working on a project that uses sha256 and security keys, I came across the term hmac. I’m still not quite sure what this is about, and I’d like to understand a little more. I have the following…
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18
votes2
answers1866
viewsWhat’s the hell with callbacks?
Going through some recent research, I came up with an unknown term for myself: "The callback Hell" or "The hell of the callbacks". I was curious and decided to research a little, arriving at the…
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18
votes3
answers713
viewsforeach is a loop or iterator? Or can it be both?
In a video tutorial the instructor stated not to fall for the nonsense of thinking that the foreach is a loop, and it was vehement that he was an iterator. There are cases where we can go through…
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18
votes1
answer2673
viewsWhat makes Python a multiparadigma programming language?
Here on this Wikipedia page cites some examples of multi-language such as C++, Groovy, Oz, Ruby, Scala, Swift, Groovy and even Python. Particularly I did not find so objective the explanation. What…
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18
votes2
answers3974
viewsWhat is "word" of a CPU
In my Operating Systems class the teacher quoted a term that left me a little confused, which is word of a CPU (Central Processing Unit) and he did not elaborate on the explanation of this term,…
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18
votes1
answer520
viewsWhat am I supposed to understand when they say ". NET"?
I’m starting to learn C#. I already understand what the Runtime and what is CLI, but turns and moves quote . NET as if it was something I should already know, but I do not understand. Just say . NET…
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18
votes2
answers429
viewsWhat is CSS Aural?
The CSS we know formats the information delivered by HTML. This information can be anything for example: image, text, video, audio or any other element created, that is, the CSS formats the…
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18
votes5
answers1252
viewsWhat are the advantages and disadvantages of using pagination and infinite scroll on websites?
What does the user gain or lose when choosing one of them? Consequently what website owner has some gain due to better user experience. When to choose each one? There is a type of website or web…
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18
votes2
answers8121
viewsWhat is a Multi-tenancy?
What is Multi-tenancy? What main approaches to implementing it?
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18
votes3
answers66206
viewsIs there a shortcut to indenting the code in Sublime 3?
It is noticeable that in several IDE’s there are some shortcuts to indent the code. For example: Eclipse(Win): Ctrl + Shift + F Android Studio(Win): Ctrl + Alt + L As everyone* knows, I assume,…
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18
votes1
answer540
viewsWhat are HTML entities?
I often see some pretty crazy codes in the middle of tags HTML, and searching falls under that term entities, then the doubts arose: What are Entities HTML and when should I use them?…
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18
votes4
answers31300
viewsHow to disable resize from textarea?
How do I disable resize of a textarea ? <textarea></textarea> I wish I couldn’t change the size of the box...…
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18
votes3
answers703
viewsCan I remove all the using I’m not using?
I took a project here ASP.NET C# and realize that I can remove several "using". I can get out of these using or not? Did the using which is not used in class can be used by someone who is using the…
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18
votes1
answer4514
viewsHow does "position: Sticky" work?
The sticky is a new property value position and I read a little bit and understood that with it it is possible to create HTML elements that behave at a time like position: fixed and in another as…
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18
votes1
answer1939
viewsComputational Geometry: Determine nearest neighbor
Is there any algorithm to solve the following problem: Given a set of points in R² and taking a k point, determine the nearest n neighbors of k.
algorithmasked 8 years, 2 months ago Andrey França 2,313 -
18
votes3
answers421
viewsTo observe an error in the iframe element with "sandbox" attribute
I have in my document one iframe with the attribute sandbox. With javasript i do reading a file Markdown and parse using the library showdonwjs and add that result to the attribute srcdoc of iframe…
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18
votes4
answers2317
viewsWhat is the use of Exclamation Mark (!) before declaring functions in Javascript?
I was reading a manual, and I was asked to start the functions like this: !function (){ }(); This exclamation mark appeared. What is the purpose of it?
javascriptasked 8 years, 3 months ago Diego Souza 16,524 -
18
votes2
answers4597
viewsWhat are the differences between HTTP 1.1 vs HTTP 1.0?
What are the differences between them, and for which case each is most recommended? We have the documentation of HTTP 1.1 and that of HTTP 1.0, but they are long, and I would like a brief…
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18
votes3
answers3547
viewsMeaning of parameters in an AJAX request
When making a request using $.ajax, What is the meaning of processData: false, contentType: false and async: false, what are these fields for? There is difference in using type: "post" or type:…
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18
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answer467
viewsAre there alternatives for reflection/introspection in C++?
I have the following problem. Given some kind of a guy T: template <typename T> I need to be able to convert an object like T on a map std::unordered_map<std::string, boost::any>…
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18
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answer27783
viewsWhat’s the difference between Modus Ponens and Modus Tollens?
Again in the study of mathematical logic, how to differentiate a proposition modus Ponens of a modus Tollens?
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18
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answers22927
viewsWhat is the meaning of the "&" (commercial) operator in the C language?
I am putting together a workbook in C and I am looking for a clear way to explain this operator to the reader, and I believe that this question will help the people who are starting. Take an…
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18
votes3
answers16110
viewsWhat is the difference between web server and application server?
What’s the difference between web server and application server? Where each one is/should be used? There is some interaction between them (a software can use the 2 technologies together)?…
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18
votes1
answer2609
viewsWhat is a "stateless protocol" like HTTP?
Lately I have been reading a lot of material about the web and I always see someone mentioning that HTTP is a stateless protocol (stateless Protocol). Follows a passage taken from RFC 2616 (my…
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18
votes2
answers847
viewsHow does running an . NET application work?
There are several terms I always hear/read when I see talk about running. NET applications, such as MSIL, CIL, IL, JIT, Jiter, Roslyn, CLR, among others I must have forgotten. I would like a brief…
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18
votes1
answer756
viewsDenial of service with stress test
First of all, a stress test, second this reply from @guiandmag is: Stress testing consists of subjecting the software to extreme situations. Basically, the stress test is based on testing the…
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18
votes4
answers607
viewsObject orientation - How to find the right abstractions?
Actually the question I’m trying to ask is exactly that: How to identify classes in an object-oriented system?. However, I would like to ask for two additions to the accepted answer. She seems to…
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18
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answer289
viewsBuild C++ using Gradle
The Gradle and a great ally in java and android development. I was looking at the site and realized that it can also manage projects in c++. How can I use it to compile a super simple project (hello…
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18
votes3
answers8119
viewsWhat are the best practices in field validation?
I created an example to illustrate my doubt regarding field validation, the example is composed of two classes Pessoa and ModelPessoa. The class Pessoa has the following attributes: Nome, Idade,…
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18
votes1
answer2002
viewsConsulting multiple Cnpjs situation in the IRS
They gave me an ungrateful mission to consult in the base of the IRS the situation of several CNPJ’s (more than 1000). Is there any programmatic way to do this, and preferably not cost?…
language-independentasked 9 years, 1 month ago Leonel Sanches da Silva 88,623 -
18
votes1
answer314
viewsIs it correct to use a block using inside another using block?
It is correct to use a block using inside another block using as in the example below? or just put the first using? public DataTable Listar(string stringMySql, CommandType commandType,…
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18
votes2
answers994
viewsWhy use a generic return?
I was looking at the signature of the class methods Optional and I don’t understand what that means <T> in front of the return of the method empty(): public static <T> Optional<T>…
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18
votes4
answers12892
viewsHow to convert float number to spellnumber in PHP?
Is there any native function, or other practical way, to get a number on float and convert to full number? Example: //input: 2.000,00 //output: dois mil…
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18
votes1
answer4077
viewsWhat is the difference between the elements <img>, <picture> and <figure>?
In HTML we have the elements <img> (image), <picture> and <figure>, which I believe to be a "figure" or "image". The img is well known, the others have been introduced recently. I…
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18
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answers4788
viewsIs it possible to use masks on mobile devices satisfactorily?
So after a true pilgrimage that yielded about 10 questions, I discovered that the masks I was wearing didn’t work properly on mobile devices. The main ones are (were?): Maskmoney inputMask What…
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18
votes2
answers10850
viewsWhat is the main difference between int. Parse() and Convert.Toint32()?
In C#, there are two ways (among others) to convert other types to int: Convert.ToInt32(valor) and Int32.Parse(valor). What is the main difference between these two forms of conversion?…
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18
votes3
answers437
viewsDatabase should follow the OO standard?
Object Orientation According to the Rules of Pure O, we have: "The Object must manipulate methods and attributes belonging only to it" That is, what does not strictly belong to class should be an…
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18
votes3
answers1166
viewsWrite Timespan in full
I want to write a static class (can be Extension) to represent the value of a structure TimeSpan in full, in Portuguese. The idea is to always compare the current date (Datetime.Now) with the date…
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18
votes2
answers484
viewsIs there an opposite for `contains`?
I have a list: List<int> lista1 = new List<int>(); lista1.Add(1); lista1.Add(2); lista1.Add(3); List<int> lista2 = new List<int>(); lista2.Add(1); lista2.Add(2); To get the…
c# .net entity-framework linq lambda-expressionsasked 9 years, 5 months ago Jedaias Rodrigues 6,718 -
18
votes3
answers18194
viewsWhat purpose of unsigned in C++
What is the purpose of unsigned in the C++? Example: unsigned char ch2;
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18
votes3
answers1132
viewsWhen to use finalizers and garbage collection in Java?
When to use the methods System.gc() and finalize()? I read that it is very useful in object orientation to destroy memory objects that are not being referenced and to finish tasks, but I see few…
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18
votes1
answer6209
viewsDifferences between getClass(). getResourceAsStream() and getClass(). getClassLoader(). getResourceAsStream()
In the need to load a resource in my project I came across these two methods. From the choice between one of the two arose some doubts about which I would like to share here. What is the motivation…
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18
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answer897
viewsStreaming type 'livestreaming' with javascript
I’m developing a project of Livestreaming(Live video streaming) and would like to know if it is possible to make this broadcast using websockets, javascript and html5 video capture where would have…
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18
votes1
answer237
viewsStack and memory align operation in MASM X64
I have an application that takes a TAC code (IL) and generates an ASM code using x64 MASM. The problem is that I’m not having any compilation error, and yes, (at least that’s what I think) at the…
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18
votes1
answer2413
viewsHow to generate a pdf file containing the digital certificate information?
I have a PHP system that generates a pdf, and I need to use the client’s Digital Certificate to sign this document. I’ve been reading documents, and I saw that the FPDF that I use does not yet…
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18
votes8
answers2700
viewsIs it good practice to mix Php and Html?
I see that in python, has the Bottle for example that does the same thing of what I intend to do then... I am new to web practices, student indeed and would like to know if I can use php and html in…
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18
votes4
answers2297
viewsIs it correct to use a table in the page layout?
I made a data table for a colleague of mine here at work and used a table, only it had no header, it had only 2 columns. And he told me that the staff hates table, which was for me to read about…
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18
votes2
answers2027
viewsWhat are operators for | & << >>?
I was analyzing a code and found some operators I don’t know: |, &, >> and <<. What is the functionality of these operators? bits = h1 << 18 | h2 << 12 | h3 << 6 |…
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18
votes3
answers4829
viewsclick a play button on the Youtube iframe
I have a iframe of Youtube, and a div above it, I want when the user clicks on that div He plays the video. My HTML: <div class="p-relative"> <div class="botaoMaior"> <div…
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18
votes3
answers10342
viewsWhat are Unions? Why use them within structs?
I’d like to understand the differences between union and struct. I realized that both can be accessed in the same way: u.membro uPrt->membro s.membro sPrt->membro In practice I have seen…