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16
votes3
answers2341
viewsGood practices using CSS
What are the best practices in CSS to maintain código limpo, compacto and manutenível? Should a simpler and less rigid form of selectors be used? (Scenario: There’s a div with an image inside)…
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16
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answers684
viewsWhat is an algorithm?
I would like to know what algorithms are. I program in C, study C++ and Python. In all the online courses I’ve taken, I’ve heard of such an algorithm, but I don’t know what it is.
algorithmasked 9 years, 8 months ago Mateus Souza 647 -
16
votes1
answer24414
viewsWhat is Maven for?
I often find large projects that have the pom.xml file, but I never understood the usefulness of it, I just found out it’s something related to Maven. Finally: What is Maven for? What is the pom.xml…
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16
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answer1779
viewsUX best practices for signage and form usability
Today I came across an interesting fact: in the last 10 years, our attention span dropped from 12 to only 5 minutes. A fact that can be confirmed by the increasing number of users of microblogs such…
uxasked 9 years, 10 months ago Eduardo Silva 3,449 -
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answers14217
viewsHow to create/maintain "global variable" in java? To log in
I’m making a desktop application in Java. This application has a login screen (Jlogin) and one with the main application (Jprincipal) and I have a Login class with methods for database query and…
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16
votes5
answers2736
viewsTest whether all characters of the first string also appear in the second
I’m trying to do that function with the help of the functions strcmp() and strncmp() and I’m not having much success. Let’s say I have the string char s[] = "abc" and another string char v[] =…
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16
votes3
answers7424
viewsWhat are the main differences between VB.NET and C#?
In addition to syntax, what are the main differences between these two languages? Is there any difference in performance between them? Or is there any case where it is extremely advisable to use one…
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16
votes2
answers17517
viewsReal difference between point operator (.) and arrow operator (->) in C?
What is the real difference between the two operators. I know the operator (->) is used when the variable is a pointer, and that it is equivalent to (*ptr).membro. Well, if I declare a pointer of…
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16
votes4
answers8313
viewsIs using addslashes against SQL injection safe?
Use the addslashes() is it really safe against SQL injection? If not, tell me why. I’ll wear mine like this addslashes() <?php $id = addslashes ( $_GET ["id"] ) ; /* Adicionei as barras */ echo…
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16
votes3
answers2621
viewsWhat is end-to-end encryption
I hear a lot about this cryptography business end-to-end but I can’t quite understand why it’s called the "safest option for privacy". I have doubts and enumerated them, see: What is? How it works?…
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answer1733
viewsWhat are the main differences between Dart and Typescript?
We already had a question comparing two languages that run on top of Javascript. I think it was necessary to compare two languages created for the purpose of creating applications for browsers and…
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16
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answers898
viewsAre business rules always related to validation?
Since I started studying object orientation I hear a lot about business rules. Basically, from what I understand until today, an object must have methods encapsulated the rules of business and the…
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answers1760
viewsWhat is the difference between "!=" and "<>" in PHP? What to use?
What’s the difference between != and <>? Which one should I wear?
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16
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answer511
viewsWhat is the technique of hiding components to ensure information?
I missed the name of this technique in which the person responsible for development rather than dealing with the problem simply hides it. Example: I have a button that when clicked causes a DROP…
security-guardasked 10 years ago Renan Gomes 19,011 -
16
votes3
answers10940
viewsHow to recover the previous commit?
After you have added modified file and have given commit, I had to modify the whole structure of the code, but it didn’t work and I wanted to have access to the previous code again. How do I…
gitasked 10 years, 1 month ago Van Ribeiro 1,482 -
16
votes2
answers316
viewsCan I use MIT along with GPL?
There are several software licenses around the world, but I have come across a problem that may sometimes even reach the level legal. And that wouldn’t be very good for my project. My software is…
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16
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answers450
viewsGetters and Setters can only "walk" together?
I am studying object orientation and am having some doubts in the encapsulation part. For example: Class Url { private $url; public function setUrl($url) { if (filter_var($url, FILTER_VALIDATE_URL))…
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16
votes3
answers3152
viewsWhen to use Setters and Getters?
I’m studying OOP and in the encapsulation part I had a question about when to use getters and setters, besides being able to validate the parameter passed, what is the usefulness of using? I could…
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16
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answers3148
viewsWhy does everyone hate multiple inheritance in C++ and what’s your difference to mixins?
I’ve always heard that multiple inheritance in C++ is chaos. Why? It wouldn’t be technically the same thing as using mixins in languages such as Ruby? And what is this abstract class of Java? It’s a…
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16
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answers4284
viewsWhat is the probability of generating a Repeated Guid?
What is the probability of generating a Repeated Guid with Guid.NewGuid()? I am uploading numerous images from my system. The same will be a Multitenancy, and will share the same Deploy, from the…
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16
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answer1184
viewsBest Practices for Insertion, Modification and Deletion with Entityframework
For deletion of records you may not have, but for Insertion and Change I believe there should already be something discussed. Probably the best practice on Insertion and Amendment is Viewmodel s,…
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answers930
viewsBehavior of different ways of comparison in Java
If for example I have the code below, I am comparing the reference of the objects in the case ex1 and ex2 and not the object itself, correct? Pessoa ex1 = new Pessoa(); Pessoa ex2 = new Pessoa();…
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answers10265
viewsUse of DTO and Viewmodel in ASP.Net MVC project
I have an ASP NET MVC 4 project with the following projects: Domain Repository Contracts (interfaces) DTO’s And the web project The web project "sees" only the repository project and it is…
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16
votes2
answers256
viewsHow to solve special situations of unnatural value for a domain?
The question has a slightly more conceptual bias, so I’m going to use a simple generic example. There are cases where some column may be in a special situation, this because an information: is not…
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16
votes1
answer10823
viewsWhat are the most files I can have in a folder?
I’m developing a web application to run on linux. In my project the visitor of my site can send images as many times as he wants. My image upload folder structure will be separated by year/month.…
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16
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answer8375
viewsWhat’s the difference between Less and Sass?
What is the difference of each and advantages and disadvantages?
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16
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answers651
viewsProblem of stopping can be solved in practice?
The halting problem can be explained as: given a program and an input for it, it will complete its execution and return a response or will enter an infinite cycle? This has been proved undecidable…
computer-theoryasked 10 years, 5 months ago Guilherme Bernal 20,024 -
16
votes5
answers7129
viewsNumber of weeks in a month
I would like to know how to calculate the number of weeks you have a month D S T Q Q S S 1 => Semana 1 2 3 4 5 6 7 8 => Semana 2 9 10 11 12 13 14 15 => Semana 3 16 17 18 19 20 21 22 =>…
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16
votes2
answers13578
viewsMysql error "expects Parameter 1 to be Resource, Boolean Given in"
$query = "Select * from servico where ID_SERVICO = $id"; $result = mysql_query($query); if($row = mysql_fetch_array($result)) { $nome = $row['NOME']; if($nome == 'Marketing') { include…
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16
votes3
answers29267
viewsBarcode Converter - Convert Barcode to Digitized Line
I’m reading the bank note barcode, but found that the barcode does not exactly match (numerically) the digitable line (also called line code, numeric code or IPTE). According to a document from…
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16
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answers6739
viewsWhat are Usability Principles?
In Interface and Interaction Design, what are (and what are) the principles of Usability?
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16
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answers958
viewsWhat is the difference between: Urlencode, Escapeuristring and Escapedatastring
And which of the three is equivalent to encodeURIComponent javascript? String: 'apostrophe' "double quotes" Stackoverflow! string teste = "'apóstrofo' \"aspas duplas\" StackOverflow!";…
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16
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answer4185
viewsWhat is the difference between the Data Mapper and Active Record Patterns?
I would like to know the main differences between these two Patterns design. I have this question because when I heard the news about Cakephp 3.0 I saw the change of the Pattern design used by the…
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16
votes3
answers864
viewsWhat happens in detail in the destruction of a variable?
I wonder what really happens behind the command unset in a variable in the PHP. I believe this happens in memory, but I would like to deepen my knowledge of this and get the certainty of what…
phpasked 10 years, 7 months ago Rogers Corrêa 2,596 -
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votes3
answers6549
viewsWhat are providers? What is the difference between OLE DB and ODBC?
I need to read files dbf. I found a tutorial to read the same where the author uses these two providers. I only saw differences in the connection string. What are these providers? What is the…
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16
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answer8416
viewsHow the Lazy Load Entity Framework works
It’s the following guys, from what I saw on Entity to use the Lazy Load you leave the property without keyword virtual, and Ager with the virtual. However, I saw in some blog posts that people use…
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16
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answers1907
viewsHow to work with websockets
I’m trying to use Websockets in PHP and Javascript and I’m confused, it uses the protocol Ws:// and wss:// and the server (hostgator) does not have these protocols enabled (I think!) and I can’t get…
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votes1
answer1772
viewsIs Nosql synonymous with an Object-Oriented Database?
Nosql is synonymous with Object-Oriented Database? If the answer is nay: What’s the difference between the two?
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16
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answers2459
viewsHow useful are Java Annotations?
When I first studied Java, when I saw about Annotations I only saw that they are useful for generating metadata, but I didn’t see anything that influenced the behavior of the program. Basically, I…
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16
votes1
answer673
viewsDoes compiling on your computer really improve performance?
Any programmer knows that when building a C/C++, the compiler can optimize the code to generate faster executables. But, it is also said that there is the compiler optimization for your processor.…
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16
votes1
answer2380
viewsXSS attacks, how does it happen?
Recently a client was the victim of XSS attacks. We handle all the faulty inputs, but I can’t understand how malicious javascript code was inserted into the files ". js" on the server. How they…
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16
votes5
answers17254
viewsGenerate multiple random numbers without repetition
I’ve made some attempts to make a function that returns random numbers that don’t repeat themselves, I’ve made some attempts but none have succeeded, if you can show me a function that does that…
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16
votes2
answers713
viewsHow to simplify the following IF in PHP?
I had to do a check to concatenate content to a variable, but I think the service got a bit "pig" and wanted to see if someone could help me simplify this check if($IdUserOnline2){ $IdsInteracoes .=…
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16
votes2
answers1842
viewsWhat is the Unicode (BOM) signature?
I noticed that sometimes Dreamweaver puts assinatura unicode (BOM) on some php’s pages, I have to remove most of the time so that there is no spacing on the display page and I’m not sure what it’s…
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16
votes1
answer1856
viewsASP.NET MVC - Attribute you write in a View
I need to write a Attribute write a mask validation in the View. Given for example a zip code field, I would like it to mark a Property in the Model with a [CEP], be written in View the following:…
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16
votes1
answer1089
viewsWhy is the "@" symbol being translated to "¿" when sent via SMS from an Android 2.3 device?
I’m developing an application for Android that sends commands to a remote device via SMS. The commands used are all common text messages, and some of them are started with the prefix A@@. To test…
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16
votes2
answers4769
viewsApply, sapply, mapply, lapply, vapply,rapply, tapply, replicate, Aggregate, by and correlates in R. When and how to use?
What is the difference between the functions apply, sapply, mapply, lapply, vapply, rapply, tapply, replicate, aggregate, by and correlates in the R? When and how to use each of them? There are…
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16
votes2
answers1480
viewsWhat is the function of operators <<, >> and >>> in Javascript
What is the function of mathematical operators <<, >> and >>> javascript? Examples: 0 or 1 >> 1 is 0 2 or 3 >> 1 is 1 4 or 5 >> 1 is 2 Same goes for negative…
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16
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answers12657
viewsHow does the site take off.com perform the search for ticket prices?
I am thinking of creating some services to monitor the prices of plane tickets and would like to know how the site takes off.com performs its research. I mean, what kind of strategy does it use,…
web-serviceasked 10 years, 11 months ago Acaz 279 -
16
votes4
answers3235
viewsIs there a Website/API to host photos on the web?
I wonder if there is any API that makes it possible to host photos on the web. Example: cloud.push(arquivo, callback, fail); I will use this API for the purpose of enabling users to host images for…