Posts by Maniero • 444,682 points
6,921 posts
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answer66
viewsA: How to set acceptable single values for an Enum property in a Serializable class?
No specific mechanism ready. It is possible to create a framework complete to treat it. Or do the simple and time to import the information treat whether it is valid or not. Generic mechanisms are…
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answer190
viewsA: Why suppress zero before the point in decimals, as in 0.5 == . 5?
What really happens when we determine a decimal without zero before the point? Nothing, this is a matter of syntax, does not change the execution, the meaning, nothing, has only one character less.…
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answers499
viewsA: Define a generic variable without defining the type
So you don’t want to use Generics. This mechanism is to have a specific type. In any case I could use a object who is the type of all kinds. I would avoid that, it’s almost never fitting in and is…
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answers109
viewsA: Is it wrong to put this much code into a button click event?
It should only have the most obvious code to execute when the button is clicked. A part of the code does not seem to have to do with the button itself, and should therefore be delegated to other…
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answer57
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answer1314
viewsA: How to know if there is content in a class object?
Let’s set things right. What you want is to know if you have content in the object and not in the class. Class is just a model. You can check if the object is null: if (usuario == null) Otherwise it…
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answer249
viewsA: Using a PHP class without instantiating it into a variable is the same thing as calling a function?
It’s not the same thing, and in fact, usually, it doesn’t make much sense. In fact methods are functions that work with a specific object. Since the constructor is a special function that creates…
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answer272
viewsA: How to generate random value pairs
I don’t know if it was you I was talking to, you need to understand what you’re doing, you’re already asking a lot of questions here and you show that you don’t understand anything that’s going on…
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answers4944
viewsA: Function to check palindrome
If the function is to check, and has this even in the name, it is highly likely that it should return whether it is true or false. And even if it wasn’t that, only if she said explicitly that she…
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answers374
viewsA: "== true" is useful for something? Is it better "!" or "== false"?
Usually when you see a code in a if compared to false or true, is doing something superfluous, since the if at all times expects a boolean, so it can only be those 2 values. Any expression that…
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answers542
viewsA: Is there a design standard or recommendation that defines the optimal amount of parameters a function should have?
It doesn’t exist, and I’m going to say that anyone who says they do loses credibility with engineers "for real". Book review A book that I think people should read was quoted in the answers. But I’m…
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answer572
viewsA: Decrease, increment and sum of pointers in C
In all of the above you are not adding pointers, you are adding up values pointed by pointer variables. This is very different, doing what you probably wanted, changing the associated values. None…
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answer245
viewsA: What are the impacts of excessive use of Try/Except (Exception Treatment)?
In Python the culture is to let the mistake happen and then treat, so it kind of doesn’t have much choice in what already exists and probably in third-party libraries that follow the same…
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answer101
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answer101
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answer167
viewsA: Can an employee be an individual?
It was recommended, in this question, to maintain the relationship between Physical Person and Employee as generalization (Employee extends Physical Person). I do not understand why it is not in…
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answers50
viewsA: Get list names that are 4 in size
You need to initialize the list outside the loop, the way you are doing each analyzed item is starting the list from scratch and you lose what you have already done. Whenever you encounter a problem…
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answers4291
viewsA: Difference between date and datetime
The difference is not only the notation is the content, it is the value that it stores. The first has no time, only the date, the second has both, this is important because it is possible to extract…
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answers186
viewsA: type’T' must be a Reference type in order to use it as Parameter 'Tentity' in the Generic type or method
Because the signature of the method you are using requires so: public virtual Microsoft.EntityFrameworkCore.DbSet<TEntity> Set<TEntity> () where TEntity : class; I put in the Github for…
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answer273
viewsA: What is the Map object for in Javascript?
They are almost identical in general, a Object is a map, but not exactly the structure Map available, so there are implementation details that differentiate them, but serve for the same thing.…
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answer498
viewsA: What’s the difference between running and executing?
I imagine it’s without the point, if it’s with the point I’d have to figure out what you’re talking about. executeQuery() as its name says, it is for consultations, almost always use a SELECT in it…
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answers409
viewsA: Sex selector on if parole
In this case you only need one character, no more than this, as the code already shows. So it changes almost nothing. #include <stdio.h> int main() { char sex, nome[200]; printf("Digite o seu…
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answers88
viewsA: Rename error message
The machine’s settings should be in English, so it would. If you cannot do this at least the language needs to be installed, and you need to configure to use our messages:…
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answers78
viewsA: How to check if variables are filled with strings? and not show them when empty
That? var obj = { cidade : undefined, estado : "", cep : "123" }; if (obj.cidade === undefined) console.log("cidade não tem valor"); if (obj.empresa === undefined) console.log("estado não tem…
javascriptanswered Maniero 444,682 -
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answer114
viewsA: Entities classes
You’re going the right way. I wonder if I should have Pessoa. This is abstractly cool, but physically I do not think should have, almost always this is a mistake and in database will only lose…
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answer205
viewsA: What are the differences between hashed or tree map implementation?
The doubt should be more reversed. If you need the data to be sorted you need the binary tree. If you need order, you need a array, or some trick with the binary tree (or not). If you can disregard…
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answers444
viewsA: MVC + DAO - Which way should I choose in PHP?
in Java, in the Template class I can create in the class funcionario the attribute Setor s, but PHP is not typed, as I could solve this association case? The way people are taught OOP is based on…
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answer1979
viewsA: I cannot identify the error - |35|error: ’d' undeclared (first use in this Function)|
As the message itself indicates, the variable remains to be declared d. You’re wearing it on the last if without it existing. A solution would be: int a = 5, b = 10, c = 15 char d = 'a'; I put in…
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answer104
viewsA: How to print 0.10 instead of 0.1 in Java?
Thus? System.out.format("%.2f%n", decimal); I put in the Github for future reference. You need to specify the number of decimals and not how it should be formatted. I hope you do not need accuracy,…
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answers418
viewsA: Is there a difference in using HTML5 attributes with or without true/false?
The first is correct, the second can work by coincidence in some browsers. A string is considered a valid value, therefore true, so just by chance it works. <input type="text"…
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answer255
viewsA: Struct and matrix, how to relate?
Yes, that is correct. No problem using this, it’s actually quite common. There are several other ways to declare, but this one looks good. Some would prefer to be explicit using the names of the…
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answer333
viewsA: The Operator + is Undefined for the argument type(s) Charsequence, int
I believe that this is the only way to work since the String be of a subtype of CharSequence: principal.quanti.setText("Você possui " + cont + " produtos cadastrados.") If you really need to, you…
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answers124
viewsA: How can I use or name constants for response type fields?
In such cases, should we use constants? Is there another alternative? If so, which? I’m not really a fan of this. It seems Zero = 0 or Um = 1. If they are constant even why not put them as…
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answer106
viewsA: Class definition within a function or another class
Generally, the smaller the scope of something, the less it pollutes the code, the more it becomes encapsulated and protected from misuse and generates fewer external concerns. Everything that is…
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answer416
viewsA: How to define in the parameters the type of arguments that should be sent?
Something like that? def a(b : int, c : str): print('Isso é um Numero: %i' %b) print('Isso eh uma String: %s' %c) I put in the Github for future reference. Possible since Python 3.5 and is improving…
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answer477
viewsA: Is the PHP Day of the Week feature limited?
Yes, it does, it’s called bug millennium II or bug of timestamp unix or Y2K38 Problem. This is because Unix determined that the time would start on 01/01/1970 and would have an accuracy that would…
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answers161
viewsA: Pointer for C functions is not calling
The biggest problem is that you are not calling any function, the call always occurs with the parentheses, equal to a normal function, in this case the variable name is equal to what would be the…
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answers143
viewsA: $_ has any meaning in question?
These are predefined variables, as stated in documentation. They are populated by the PHP virtual execution machine according to the execution context, so they are like exposed internal objects for…
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answer119
viewsA: What does it mean in PHP when mysqli_num_rows returns -1?
Are you sure you got this in this role? A documentation does not indicate that this is possible, but does not indicate that it does not happen. The PHP documentation is really bad, so I think there…
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answers240
viewsA: Specialization and generalization in databases and application development
Is there any reason to have a specialization? If so, is there any reason to have a generalization? It may seem obvious, but one of the two seems to be wrong in relational modeling. If you’re talking…
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answers106
viewsA: How to create unmanaged variables?
The Garbage Collector does not manage variables, so the question in this way makes no sense. It manages allocated objects in the heap managed by him. When you create a variable in your code it…
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answers560
viewsA: What exactly does '%02x' do?
According to the documentation displays the integer as hexadecimal ensuring it always has 2 digits, with 0 used on the left if it has only 1 or 0 digits. It is usually the only way to generate…
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answer75
viewsA: Create a table or several in SQL Server?
Each is valid according to the need that has not been specified. Modeling is understanding the problem as a whole, in every detail, in every comma, analyzing what can happen in the future. Slowing…
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answer177
viewsA: Split() problem in Mono
In fact, finally there’s a new overload of the method Split() no. NET Core. Finally! That’s why I always recommend it. There is no . NET Standard, and why it is not in Mono or . NET Framework. Use…
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answer73
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answer141
viewsA: Deploying with SVN
Which directory to use locally ? For example, my current directory /localhost/app and I have the code there: a) I should create the SVN in the same folder (because that’s where I’ll change) and then…
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answer459
viewsA: Creating a C#Client-Server architecture
When we speak on server the system business layer is all on the server or client as well, since I reference the business DLL in the presentation application? It depends. This can indicate that you…
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answer455
viewsA: How did the command-line interface (CLI) come about and what was this need?
He always did, only it was so natural that nobody talked about it much. One of the reasons is the increased complexity of managing these tools. And people tend to be more productive using simple…
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answers223
viewsA: In SQL queries should I follow the order of the index?
Depends on database implementation (none mainstream that I know of, except for an improbable bug), most of it doesn’t matter, it will find the best way to use the index, at least in the simplest…