Posts by Maniero • 444,682 points
6,921 posts
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13
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answers10585
viewsA: What is database normalization?
The question already has a very good answer, almost a chapter of a book giving all the details, but I missed something important in it that I realize that many people confuse or do not understand…
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answer88
viewsA: Does the shuffling function have traps not easily perceived?
Not in general, in particular we can not say because we do not know what you want, if it solves what you need. This algorithm even has a name, it’s called Fisher-Yates, and it’s the most used for…
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answer113
viewsA: How should I assign strings in C#?
Behind the scenes, by assigning another text in a, it will create another instance of a. Is that right or am I saying something wrong? Not exactly, in this example you are "creating" another…
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answers143
viewsA: Is there an advantage in languages that package (.dll, .class, .exe) for scripting languages (.php, .py, .js)?
Yes. And there are drawbacks too, as in everything. In security issue no, it may be slightly more difficult (but in all cases it is possible to access the source code, only it will not be a code as…
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answer134
viewsA: Nomenclature of tables with company name and system acronym
There is, if the same database has multiple companies. It’s a modeling error, it’s finding a solution to a problem created by a wrong decision. Then you better use schemas or even just another…
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answer156
viewsA: The radio button is behaving like a checkbox and does not allow selecting or unchecking the option
For you to have a group of radio buttons, that is, that allow one button turned off the other you have to give the same name to all elements of that group. Your code doesn’t even have a name (name),…
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answer95
viewsA: C++ language standard for pointer
The first is the most suitable for sure. In fact in essence no one does the second except to demonstrate that it is possible (and that it is a syntax sugar) or if you have a very specific case (I’m…
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answers172
viewsA: Initialize variable in a "for"
There’s a lot of confusion there. In C you are not required to initialize the variable with a value, but this is always an error to use in a for because it gets unpredictable from where he’s going…
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answer117
viewsA: Is it bad practice to use "Guid" and "int" for the same bank?
Right or wrong depends on context, there is no magic answer that can always or can never. You have to ask yourself what problems you expect to have? And why do you need to mix things up? And why did…
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answer279
viewsA: java:7: error: invalid method declaration; Return type required
The error itself is exactly what is described by the compiler, speaks the type of return of the method. If there is no return then the type is void, thus: public cliente() { I put in the Github for…
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answer101
viewsA: Bizarre error with dynamic allocation
Clearly there’s a mistake there. You’re allocating 10 bytes. Then it allows someone to enter data freely, that is, someone can type something larger than 10 bytes without any restriction, which will…
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answers590
viewsA: How do I receive a value for each double variable on the console?
Directly you cannot do this with the infrastructure . NET provides. Either you have to access the console directly from the API of the operating system, which is quite complicated, or you have to…
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answers17559
viewsA: Mysqli vs PDO - which is the most recommended one to use?
I decided to answer, even knowing that this answer will never have more votes and it will seem that it is not so good, because there has been a lot of false information being spread around, the…
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answers224
viewsA: Function values returning Undefined in Javascript
They are undefined because they don’t exist. You’re trying to access an object that in theory should have these members, but what you have is an object with a unique numerical value without members.…
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answers389
viewsA: What is the function of the keys { } in this interpolation?
The key function is to avoid ambiguity. As in interpolation it is possible to use any valid expression in code in some situations it may be that the compiler does not know what to do and determine…
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answer79
viewsA: What are Widening and Narrowing conversions?
Widening It is to take a value and treat it as something broader, that is, you take a value that has a smaller magnitude and put in a type that allows a greater magnitude, so there will never be…
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answer37
viewsA: What is the origin of conflicts between libraries?
This is really rare and occurs only when the code has no form of namespace, even if informal (i.e., bad code). If you have two static libraries that have a similar symbol present in both of them you…
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answer154
viewsA: Do you need to allocate memory when you have struct inside another struct?
That’s not the point. I think it’s dangerous to make such a complex code without understanding what you’re doing, I would reverse it. I don’t even know if you need one malloc() there. Could be, I’m…
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answer87
viewsA: What happens to memory space after the use of a local variable?
Obviously it depends on the language and even the implementation of it if the specification of the language leave this book. In general local variables are allocated in the stack and at the end of…
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answer36
viewsA: What is the meaning of the "raced" result in Firefox?
This occurs when an object is being accessed by more than one thread, either by failure of Firefox itself, or by failure of script of the page that is rotating there. This is called running…
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answers189
viewsA: Why do we not receive an error when we call an undeclared variable as a window property?
Javascript is a language full of oddities because it was set very quickly. The main bad decision was to have weak typing, and worse, they adopted very bad criteria to transform one type into another…
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answer217
viewsA: How will the null coalescence assignment operator work in PHP 7.4?
What will happen in this case? It’s PHP, isn’t it? So you see, anything can happen :D But if all goes well and they made the right decisions (ok, they must have made it because they set this case as…
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answers174
viewsA: Request and Pedidoitem establish a composition?
There are controversies about the letter A, so I find it at least dubious. At the same time contests usually provide literature to study that can say what is written there and it would be so that…
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answers758
viewsA: What is Fat JAR?
Normal is your classes to be compiled for files jar individual, with Fat Jar you have everything in one file. That’s it. There is an advantage because files do not get loose and cannot be deleted…
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answers454
viewsA: How to write acronyms in camelCase?
This has a little to do with taste, and what I always say, no matter how consistent it is. Consistency has to do with the team you work with, and it has to do with the culture of the technology…
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answers274
viewsA: Placing two functions within one
Writing short code should not be a goal. Writing expressive and canonical codes should be something to be pursued. Trying to write everything in one line has nothing more expressive or canonical.…
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answer93
viewsA: I can’t access the function
First of all, this has nothing to do with the function, it has to do with her return, or more precisely with how she’s manipulating that return. You can do this, but you should also treat the…
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answers178
viewsA: What is this if trying to say?
Contrary to what people believe if just decides to do something if it has a real value, or does nothing or falls into the else if it has a false value. This thing has a condition in the if is an…
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answer143
viewsA: What is the need to declare the constructor/super of an extended class?
Every class has a default constructor created that you don’t even see, if you didn’t have it you couldn’t instantiate the class. In classes that are derived from other constructors this constructor…
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answers780
viewsA: What are these specific purpose registers?
I would start reading How a computer understands binary code?. PC - is the registrar used to determine which address it should run next. Every executed instruction makes it move to the next…
architecture-computersanswered Maniero 444,682 -
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answer72
viewsA: Variable validation
The question does not say what you want to get as a result. The first line of code will get the text if the variable does not exist or has a null value and it only makes sense to use it as part of a…
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answers284
viewsA: Is it safe to leave crucial information in an Hidden input in HTML?
Everything in the customer’s machine is manipulable. Everything you receive from outside your server is unreliable. If your server is not absolutely safe and your code cannot be trusted (an absurd…
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answers165
viewsA: Variable appears as undeclared when trying to use it in the "while" loop
The problem is that the while is not inside the block between keys, it is outside, so it only sees variables that have been declared outside. Study on scope. Also has a block after the while that…
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answers114
viewsA: What is the function of Asreadonly() in C#?
Its function is to create an object (ReadOnlyCollection) that guarantees the contract that the original object will not be changed, this way you can pass to methods, possibly in another execution…
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answer168
viewsA: What is a static table in SQL Server?
In fact it is only a concept and as far as I know there is nothing in SQL Server or other database that defines this clearly as a mechanism (in Mysql only using Myisam there is the term for…
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answers69
viewsA: What is the difference between these two statements?
The two are creating a variable of the type Ponto, the first does not create an instance of the object of type Ponto and if you try to access then it will give a build error, initializing after the…
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answer53
viewsA: Why can I assign an instance of a class to a variable whose type is the interface?
Interfaces are contracts, so they only exist to control access to members of an object, they don’t determine what the object really is, just what they’re able to do (even when they have an…
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answers113
viewsA: isinstance() does not produce the expected result after a data entry
That’s right, if you look at documentation of input() will see that it results in a string, then it wouldn’t make any sense to go into if. You’ll probably want to turn this into a whole with the…
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answer66
viewsA: At what point do syntaxes in programming languages become important?
We do not have discussions here, we give objective or subjective answers based at least on the person’s experience. I am a "scholar" of programming languages and for a long time I was a lover of…
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answers694
viewsA: Why not comment on the code?
Uncle Bob has a way of doing it and it may not be the right one for everyone, he has his context, you have yours and I have mine. You should find what’s best for you and your team. His books and a…
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answers207
viewsA: Use different screen resolution according to the monitor
Have it, do it all over again considering it’s gonna run on a machine that’s not yours and never believe in one of the most famous programming memes. Or you redo all screens thinking of the minimum…
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answer85
viewsA: Is there a loop loop behind the code of a CTE?
It’s not just CTE, it’s all SQL. SQL is a language (not programming as some think) declarative, IE, you say what you want and is the problem of engine who’s behind her working it out the best way he…
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answer129
viewsA: How to set instance variable using the read value of a Scanner?
This code has a huge amount of typing errors (and des organization that does not prevent the compilation) and this is what is preventing it to work, but I decided to answer (although it may be…
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answers884
viewsA: Problem with currency percentage and rounding
The calculation is being done conceptually wrong. It’s not just a rounding problem. Although rare, only not rounding can give difference the same way because at a point there at the end of the…
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answer76
viewsA: Data structure in C# for neighbor-nearest?
Not much information was given so I can’t help with something more detailed, but there is no proper data structure for this. Indeed for its precise description of classified data structure (is a…
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answers8360
viewsA: What do GMT and UTC stand for?
Important question to better understand the whole concept. GMT - Greenwich Mean Time UTC - Coordinated Universal Time The GMT is the time considered to be time 0 and from there it decreases or…
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answer88
viewsA: Is there any SVN for database?
There is, SVN. You can also use Git and other normal versioning tools. The structure of DB is expressed by a text with a code we call DDL (Data Definition Language) where the command CREATE TABLE is…
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answers242
viewsA: Function in C that deletes a given string
The accepted answer has something that works, but it is not efficient having several hidden loops that make the execution very slow, so it does the same efficiently (this is a mini parser):…
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answers607
viewsA: Declaring a string in C
First, without the context of where this statement is, it is difficult to give a good answer. If it is global it is one thing, if it is local it is another. I’ll consider it local, but if it’s…
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answers154
viewsA: How to "mount" a multiple variable?
Yes, it is possible, it is one of the most basic and known techniques of programming. You do this with a variable of type array. A array is a variable that stores variables and so you can access…