Posts by Maniero • 444,682 points
6,921 posts
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viewsA: How does -O3 optimization break some programs?
Some compilers end up establishing a specific behavior that they want to treat that language specified as of undefined behavior. There is some controversy. In my understanding the compiler can do…
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answers665
viewsA: What is a regular expression?
Is a string that defines a search pattern. It is an algorithm. We can say that it is a language for finding patterns in text. She’s not a programming language, but its implementation is available in…
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answer237
viewsA: What is Guidattribute for and why?
The GUID is a way to create a stable unique identifier (an identity) (will not change) for some object in a way that does not depend on any central mechanism that ensures uniqueness in independent…
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answers1511
viewsA: Cipher de Vigenere
It took me a long time to understand what the code was supposed to do. Now I liked the joke and did what should have been done. I separated the interface part of the algorithm, gave better names for…
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answer96
viewsA: Readline does not ask for data typing
This code has several technical and conceptual errors and escapes from the modern regular language of C#. Prefer to use the names of the types that the language uses, prefer, int, string, bool. You…
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answer112
viewsA: IsGenericType, GetGenericTypeDefinition e Nullable.GetUnderlyingType
Has information about reflection here on the site. Code types running on . NET have metadata various about its composition issued by the compiler. You can access this data from the method GetType()…
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answer342
viewsA: How to make the keydown function work with the program in the background?
You have register a global key in Windows. I have picked a response in the OS with what you must do: Import the Win32 functions: // DLL libraries used to manage hotkeys [DllImport("user32.dll")]…
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answer568
viewsA: I am unable to pass one vector per parameter in C
The problem is that you did not type in the parameters and return function. It is also wrong to pass the two vectors with the operator &. A array is already a pointer, so this operator should…
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answer505
viewsA: What is an "output_buffer"?
Buffer When we talk about buffer we’re talking about buffer data, not to be confused with the term used in other contexts even in computing. It is a memory area reserved for temporary storage of…
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answer72
viewsA: Run fast things synchronously and time-consuming things asynchronously?
No, there’s no way you’re doing this. In this specific case arming and controlling all asynchronicity infrastructure will take absurdly longer than the execution of this method. The recommendation…
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answers721
viewsA: Error in C printf
You have printed the address of cont since you used the operator &. If you want to print the counter, have it printed and not other information. If you wanted to print a pointer you could use…
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answer234
viewsA: Use of assert instead of if
The reason even has to do with performance yes. The function assert() can be switched on or off with a compiler directive. So while testing you leave it on, so if there is a programming error, ie in…
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answer370
viewsA: Variable declaration with ! at end Swift 3
There are data that are packaged in one type Optional where you may have a value or you may not have one. If you do not have a runtime error. So you need to check first if it is possible to use that…
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answers1660
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viewsA: Using "String.Replace()" the string remains the same
Simple: tt = tt.Replace("\u00e7", "c"); Variables are immutable, then when you use the method, it does not alter itself string, it generates a new one and returns it to you to do what you want with…
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answer687
viewsA: How does the frame-Pointer work?
I don’t know how much you know about these low-level things and how memory works. This can help if you don’t know much. The frame Pointer, or inter-base as it is also called, it is a sub-stack of…
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answers606
viewsA: What is a tail recursion?
I imagine you understand well about recursion, when to use and its advantage over tie. You must also know how the call stack and that the memory for this has a fixed size determined at the start of…
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answer21967
viewsA: What is . in <form action="." method="post">?
This is only related to HTML. The client has to send the form data to some page, and there on action you say which, so far you already know. If you want to send to the page itself where is the form…
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answer520
viewsA: What am I supposed to understand when they say ". NET"?
.NET alone era used informally to designate technologies related to CLI (Common Language Infrastructure). Because of this it is common to say that . NET is a platform. Actually CLI is really the…
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answers586
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answers644
viewsA: Arc tangent function in C#
To documentation says that the method input should be in radians and you are using degrees. It has to convert radian to degree before. The calculator is already in degrees, so it worked. using…
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answer150
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viewsA: How is the Global Unique Identifier (GUID) generated?
How is that possible? Large numbers (2 to 128) have nearly infinite capacity. There is no guarantee that the GUID will always be unique. There are even versions that guarantee, but you can use the…
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answers11603
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answer224
viewsA: How to implement unit tests for Clipper?
I found the hbunit. I don’t know if it’s good, if it works, or how you use it, but it seems easy to take with what’s in the repository, I can only give my opinion that I don’t like the style of code…
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answer326
viewsA: Torque conversion limit in C
The problem is that it’s returning one int which has a limited capacity. I changed the code to use long which will allow larger numbers. But it has limit too. So what’s the problem? Trying to make a…
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answer76
viewsA: Error: argument of type char is incompatible with lpcwstr
The function is asking for a multibyte string then use L"PXG Cliente". I would take advantage and use the FindWindowEx() which is more modern. You must be using several legacy things in this code.…
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answers302
viewsA: What is the cost of calling many functions?
Performance The cost of calling function is small or large depending on how you look. In general the cost is to save some registers in memory (most likely will be in the L1 cache which is very fast)…
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answer301
viewsA: Show typed string string
You’ll have to wear one array (vector) so that a variable has several indexed memory positions. Have you apprehended matrix at school? It is basically a matrix with only one dimension. So actually…
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answer750
viewsA: What is "idiomatic expression" in programming?
It has relationship with elegant programming yes. It is not elegant to produce non-idiomatic codes. But elegance is not everything in programming. Idiom or idiom is the most elegant way of doing a…
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answer58
viewsA: How does a historical debugger work?
I do not know deeply but I know in general. We have behaviors and states. That is, algorithms and data structures. Behaviors are inherent to the application and do not change. States exist during…
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viewsA: Language for processing business rules
If you need something on the server and mobile you can use Xamarin and stay in the C#. I don’t think I really need a language of script, but if you really need to, you can C# itself as script? This…
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answer14872
viewsA: What is Hashcode and what is its purpose?
The term hash "usually" is translated by scattering. Some people may say it’s shredding (the die until it’s a little bit). Usages Table hash The main purpose is to use in key tables hash that need…
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answer2762
viewsA: Why in file and folder names, are some characters still not accepted?
Basically it is a problem of ambiguity in Parsing. It’s a problem similar to what we have in strings in languages where some characters are special, such as the quotation marks themselves, the…
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answer220
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viewsQ: When to use "inline"?
Everybody says you don’t have to use inline functions since the compiler knows what to do better than the programmer. But if it has in the language it should serve for something. Is it useful in any…
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viewsA: When to use "inline"?
The inline exists to give a hint to the compiler of what to do. It is in the C and C++ specification that it is like this. The compiler does not need to follow this hint. It can linearize the…
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answers306
viewsA: Any ASP.NET MVC solution for SQL injection?
You need to use SQLCommand. Thus their query will be mounted by ADO.NET reliably. If you try to do the cleaning, you will certainly make a mistake, out of the huge work that it gives. This class has…
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answer1127
viewsA: How to fill an Arraylist with values of another Arraylist caught randomly?
This code has several red flags, but I will focus only on what you need for the question. What you want is to shuffle the array. Java has it ready. Use the method shuffle(). You don’t even have to…
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answer1573
viewsQ: Why do the arrays index and other sequences start at zero?
Why the array does not start with 1? There is some technical reason to have adopted 0?
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answer1573
viewsA: Why do the arrays index and other sequences start at zero?
It has a mathematical basis. If the first natural number is zero, why computers should do it differently? You may be thinking, "in math matrices begin at 1". Yes, but this runs away from the pattern…
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viewsA: Dynamic matrix allocation in C++
If you are going to program in C++, use vector with two dimensions. The array old should be avoided in C++. Other structures may be useful too. #include <iostream> #include <vector>…
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answers17530
viewsA: Why do we have to use the attribute self as an argument in the methods?
At first self is just one parameter like any other. In it you receive an object and then through this variable, after all every parameter is also a variable, you will access the members of that…
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answer527
viewsA: Eliminating spaces in excess of a text
I was on the right track, I just needed to find the condition that would determine whether or not space should be copied. Knowing this the algorithm can be very simple. What should you copy? All…
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answer135
viewsA: When and why use the Obsolete attribute?
In simple, internal things (no one outside your team or yourself will use your code) do not need to use it anyway. You have full control over the use and if that was used, you can quickly with the…
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answers183
viewsA: Can I use C# (through Visual Studio) to develop a program for Mac/OSX?
Yes, it is possible through Xamarin Platform. You can use the Visual Studio traditional, but it does not give much support to Mac and will suffer. You will probably prefer Xamarin Studio on Mac…
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answers1521
viewsA: Cannot implicitly Convert type 'string' to 'int'
You have to have the conversion done. As the data may not be valid you have to test to see if the conversion has run correctly. This is done with TryParse(). protected void btnSave_Click(object…
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answers540
viewsA: How does an index improve the performance of a query?
It is pure mathematics! I won’t go into detail (it’s true :) ), specific doubts can be resolved in new questions. Binary search The index of a database is not at all different from a book index, or…