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17
votes1
answer26770
viewsWhat is XML <! [CDATA []]> for?
In some examples of platforms, has among the tags the <![CDATA []]>, but what’s it for in XML after all? Template for an XML to be followed by a platform. <?xml version="1.0"…
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17
votes4
answers847
viewsHow to generate indented code?
How to print indented code when I give one echo by PHP? let’s say the structure is like this: echo '<div>'. '<table>'. '<tr>'. '<td>'. '</td>'. '</tr>'.…
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17
votes1
answer1818
viewsMeta tags for Social Networks
We know that it is necessary to implement specific meta tags in <head> of our websites to optimize content sharing on social networks such as Twitter, Google+, Pinterest and Facebook. For this…
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17
votes5
answers2046
viewsCompressing PDF files
Is there such a site PDF compressor which compresses the files of 300k in 90k, I was googling and I couldn’t find anything related to do on c#. Does anyone know of an algorithm that does the same…
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17
votes3
answers8471
viewsIs a subquery in SELECT calculated for each result or just once?
Based on this example, where the result will be used to calculate the percentage of occurrence of each 'guy', which approach is more efficient/faster? Use a subquery in the SELECT to calculate the…
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17
votes2
answers1806
viewsWhy does a calculation with positive numbers give a negative result?
Why does this one count (100 * 22118400) / 44954676 in Java gives a negative number? -46 /* package whatever; // don't place package name! */ import java.util.*; import java.lang.*; import…
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17
votes1
answer484
viewsData access performance in heap and stack and object allocation
Data access in the stack is faster than in heap? And why allocate an object to heap?
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17
votes2
answers14623
viewsWhat is and what is "2>&1" for?
When we want to direct the output in order to execute a command without receiving any information, among which potential execution errors we use: meuComando >/dev/null 2>&1 Effectively…
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17
votes2
answers9060
viewsBest practice for logging the system
What is the best practice for registering a log system? public void inserirLog(string Acao) { StringBuilder csql = new StringBuilder(); csql.Append("insert into Log (Acao,data) values(");…
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17
votes2
answers618
viewsHow can we not allow indexing by search engines?
Those days I put my domain in Google and he got my Web Site and my System. I wish my System was hidden from Google and any other search engine. You could do that? And how to get indexing already…
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17
votes2
answers18486
viewsWhat is the Role attribute for?
I’ve seen a code that had that tag on it Role in a form, but I didn’t understand its use. Something like: <form role="search"> </form> What’s the tag for role in HTML5 ?…
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17
votes3
answers5444
viewsHow to calculate mathematical expressions in a string?
I’m making an application picks up an expression. How do I calculate the result of an expression? For example: 3(-9)+50/2. This expression is typed in TextView.
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17
votes1
answer659
viewsWhat is the function of '@' (arroba) at the beginning of PHP expressions
What is the function of @ at the beginning of PHP expressions? I have seen in some classes and could not get the function to put this @ at first.
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17
votes7
answers9711
viewsRemove accents
I need to know how to remove the accents of a die in a column. # Eu tentei > library(stringr) > a <- dados$Municipio[2] > a [1] "Arapeí" > str_replace_all(a, "[í]", "i") [1]…
rasked 10 years ago Lucas Guimarães 171 -
17
votes1
answer2508
viewsHow to develop two versions of the same application, one free and the other paid?
I’m starting the development of an application for Android using Android Studio, I intend to make it available in two versions, one paid, with more features, and one free, more basic. I thought…
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17
votes2
answers2365
viewsAre JS native objects associative arrays?
And the arrays are like native objects of JS? What about literal strings/primitive data? What I understand is that they are instances of the object string, but with the difference of being arrays…
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17
votes2
answers13586
viewsUse of $_REQUEST instead of $_GET, $_POST and $_COOKIE
In PHP we have available the global variable $_REQUEST which can be used instead of using the global variables individually $_GET, $_POST and $_COOKIE. For example: <?php // utilizar $bubu =…
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17
votes2
answers6315
viewsHeap of Java memory
I would like a simple explanation of what heap memory of JVM? I searched on Google but had no clear enough answer.
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17
votes1
answer5399
viewsWhat types of collections and their differences in java?
There are many types of java collections and I have difficulty knowing the following questions presented below: What are the differences between them? What situations and/or cases should I use each…
javaasked 10 years, 4 months ago Pedro Rangel 2,747 -
17
votes2
answers40473
viewsHow to create a vector of variable size?
In C language, it is possible to create a vector of any type so that its size is variable? If possible, how to do?
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17
votes1
answer4912
viewsSafely remember user
That question does not refer to password security, or data encryption itself. The question is more logical. I would like to know what’s the safest way to create that scheme "remind me". I was…
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17
votes3
answers72012
viewsGlobal variable in Javascript
How to make a global variable in Javascript? I need the variable that was declared in one function to work in another function. Example: Jsfiddle $("#div3").click(function() { var fill = "a"; });…
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17
votes8
answers34672
viewsConvert every first letter of every word into uppercase
I have the following question: Write a titleize(text) function that converts every first letter of every word into uppercase. ex: titleize("this IS just A Text"); // correct output -> (This Is…
javascriptasked 10 years, 4 months ago David Bastos 355 -
17
votes2
answers4679
viewsHow to get the list of devices connected to the network
I need to find the devices connected to the network on which my program runs. It is a network via Wifi (I do not know if this changes the difficulty of the thing), where I know that there are at…
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17
votes1
answer85227
viewsJavascript generating float with multiple decimals
When creating an order calculation system (quantity x value) I realized that in some cases when adding broken values Javascript returns numbers with many other decimal places more than expected.…
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17
votes4
answers793
viewsSimple Teaching of Pointers
I’m a sporadic programmer, and whenever I need to use pointers, I realize I’ve forgotten how to use it, and I have to work hard to learn everything again. Does anyone have any simple didactics to…
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17
votes2
answers4840
viewsWhat are AMD and Commonjs?
Recently I’ve heard a lot about Asynchronous Module Definition (AMD) and Commonjs. It seems like two terms are in fashion. I read some things about, but I’m still confused. AMD and Commonjs are…
javascript software-architecture software-engineeringasked 10 years, 6 months ago Guilherme de Jesus Santos 6,566 -
17
votes5
answers1347
viewsSingleton or class and statics?
I was researching some projects in .Net and Java and from what I understand of the benefits of Singleton, I found it unnecessary to use it. For example: in a project it was used to instantiate…
pattern-designasked 10 years, 6 months ago Gustavo Piucco 2,401 -
17
votes3
answers7027
viewsMatch php variable to javascript variable
I’m trying to do something like this: <script type="text/javascript"> function guardar_alteracoes(){ <?php $nome = ?>$('#nome').val();<?php; ?> } </script> That is, I want to…
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17
votes2
answers3267
viewsWhen and why should we use polymorphism?
When and why should we use polymorphism in Java, because so far I’ve only used it to make multiple windows based on a model. The polymorphism the way I’m applying is better than making one window…
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17
votes4
answers12575
viewsWhat does "0x" mean at the beginning of hexadecimal numbers?
I realized that when it comes to hexadecimal numbers sometimes one is placed 0x in front. For example, 0xA1B2C3 instead of A1B2C3. What is that 0x means?…
hexadecimalasked 10 years, 6 months ago user7261 -
17
votes2
answers9076
viewsMVC Asp.net paging
Currently I work with the data like this: Context returns to me all Bank Customers public IEnumerable<Clientes> ListarTodos() { return contexto.Clientes.ToList(); } In the controller I call…
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17
votes2
answers3105
viewsWhat is the question mark in a query?
Use ? in a query really avoids the SQL Injection? Avoids 100%? I saw this code and I heard many people talking about it, saying it helps in this case and how to use it? Could someone give a better…
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17
votes1
answer8180
viewsWhat is a minimal generating tree?
I have an exercise to solve and the teacher told me that I would just use this method to solve. What is a minimal generating tree and how can I use it in practice?
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17
votes1
answer569
viewsWhat is Sargable argument?
In database queries what is the concept of a sargable argument (Search Argument Able)?
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17
votes3
answers104158
viewsHow to solve a Notice: Undefined index?
Starting in PHP and following a tutorial I used the above code and ended up getting this error: Notice: Undefined index: Submit in C: wamp www mezzo-com reservas.php on line 3 How to solve it?…
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17
votes2
answers28085
viewsWhat are schemas? What are the advantages of using it?
In which situations your use is recommended?
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17
votes2
answers5822
viewsWhat is aspect-oriented programming?
What is aspect-oriented programming? I heard about it in a conversation between colleagues these days. Nobody explained me well and more, said it was something bad.
software-engineeringasked 10 years, 7 months ago Caique C. 2,785 -
17
votes1
answer655
viewsAlternatives to the (anti-)standard Entity-Attribute-Value
I am working on two systems that have a common feature: entities whose attributes are dynamic (i.e. cannot be "plastered" - hardcoded), need to be consulted in search operations (result filter), but…
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17
votes1
answer2946
viewsHow are applications made in C# Windows Forms updated, with version control?
What would be the step by step of such update so that the software after going through some change or update this is reflected to the systems that have the same software?
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17
votes2
answers40729
viewsDifference between CROSS APPLY and OUTER APPLY?
What’s the difference between CROSS APPLY and OUTER APPLY? How do they work? In what situation can they be used? It would be possible to show some examples?
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17
votes3
answers4757
viewsHow do I make a Marquee without the <Marquee> tag?
I need to wear one Marquee, but as everyone is saying Marquee is a prehistoric thing and should not be used anymore, I am in doubt as to what to use in his place. On the site of MDN says this: This…
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17
votes3
answers9289
viewsHow to change the title of each PHP page dynamically?
I know almost nothing about PHP. Once a friend sent me a code that allowed me to separate my page into several parts and then pick up those parts again in case I change something in the scripts and…
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17
votes4
answers3280
viewsInteger with 0 to the left is printed as another number
I have this code: $mob_numbers= array(02345674, 12345675, 22345676, 32345677); echo ($mob_numbers[0]); I wanted to print out the first element of array but the output that is: 641980 Why does that…
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17
votes4
answers7742
viewsHow does grid system work?
I’m using Bootstrap in a project, but so far I do not understand how the structure of it works. It uses grids but the documentation is not very clear on how it works and how to use. I want to put…
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17
votes2
answers964
viewsWhy doesn’t polymorphism work with Generics?
When trying to compile the following code I got an error. import java.util.*; class Animal { } class Cachorro extends Animal { } public class TestePoli { public static void main(String[] args) {…
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17
votes1
answer410
viewsDiscrepant running times in parallel programming
I made a parallel code in C in order to verify its execution time. Was treated: Threads; Mutex; False Sharing; Synchronization. When executing the time of Linux with the execution of the code, in…
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17
votes8
answers45427
viewsHow to disable the scroll of a web page?
I’ve been trying to disable one-page scrolling. All I have found are type solutions: #container{ overflow: hidden; } But that’s just occult scroll bar. How I would disable scrolling, even with it…
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17
votes5
answers453
viewsIs it legal to delete this in a member function?
The language delete this serves for an object to commit suicide. For example: void Recurso::release() { --refs; if (refs == 0) delete this; // Aqui o 'this' pode ser um ponteiro inválido, // tocar o…
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17
votes2
answers4913
viewsHow to check if a file is in use without launching C#exception
I have an application that processes a file queue. I need to open the files for reading and writing. Sometimes the files are in use when I go to process them. How can I check if the file is in use?…