Posts by Maniero • 444,682 points
6,921 posts
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answer240
viewsA: 'function name_name': identifier not found
Just put the statement and leaves the definition for later: void criaPoli1(int &val, int &expo, poli *topo1); Might even make: void criaPoli1(int &, int &, poli *); I put in the…
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answers2835
viewsA: What is the difference between <q>, <blockquote> and <cite> tags in HTML? And how to use them correctly?
In theory each can be used almost for the same purpose, but it should not, the correct use is semantic and indicates the intention of what you are doing. Note that the presentation can be customized…
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answer499
viewsA: COUNT(*) x COUNT(1) x COUNT(id)
select COUNT(*) from tabela Take all table columns during the query, then all data will be available in memory for SGDB to do the counting operation and other things. If there’s no optimization. But…
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answer3811
viewsA: How to finish executing code in Python 3?
If you want to close the execution then you should use a exit() and not a break. It should actually be a if and not a while that makes no sense there. If used within a function (that I prefer to…
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answers188
viewsA: Is there a difference in performance between "new" and "clone" in PHP?
It doesn’t matter. For two reasons. PHP is a language of script So if the performance is important, the language is wrong. You have an absurdly greater gain than worrying about it. As Donald Knuth…
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answer105
viewsA: Error creating variable inside IF
Let’s look at the code that matters: !$true1 && !($id = true) The first expression to be evaluated is the negation of the variable $true1. The result is false. As next comes an operator of…
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answer452
viewsA: Know the size of each element of a list
Only use the Any. if (imagens.Any(x => x.Length > 1_000_000)) //aí escolhe o que fazer I put in the Github for future reference. But don’t make an exception, this is inappropriate. Flow…
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answer54
viewsA: Infinite loop in height growth analysis
Stated how float use the formatting of scanf() as %f. You have to test to see if Gustavo grows smaller or equal to Juliano, otherwise it will always be infinite anyway, is mathematician. And it…
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answers110
viewsA: How to do for every time you pass "true", it print the entire instantiated object?
The question does not give many details, but it would be something like this: for (Produto produto : ListaDeProdutos ) { if (produto.nome.contains("Banda")) { System.out.println(produto.nome);…
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answers2069
viewsA: Display the highest and lowest value between two integers when they are different from each other
You started out well using the else in the first if, should have stayed that way. So when v1 is greater than v2 already has reason to write which is bigger and which is smaller at the same time. And…
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answer776
viewsA: When and where to use the terms: time complexity, space complexity?
Because it has to do with two things. Complexity can be measured in these two axes: runtime and occupied space. These are the factors that matter when creating or using an algorithm. How long it…
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answer127
viewsA: What is the use / reason for the existence of new Object();?
The question should be "why shouldn’t there be new Object()?". Contrary to what many people think (even if you say you don’t think so), the construction of language follows a logic, has a grammar.…
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answers2035
viewsA: What is the Python semicolon function?
It is only necessary if you want to put an extra command on the same line, so it works as a command separator. Obviously it is allowed to put it on and then leave nothing, which makes it appear as…
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answers595
viewsA: "Operator" square brackets [] when creating the arrangement in C
In this case it is not an operator, it is an identical syntax with different semantics. On this line it is not operating anything, it is only declaring. The compiler differentiates by the context it…
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answers691
viewsA: Method Reverse returns None
That’s how it works: teste = ['audi', 'subaru', 'fiat', 'ford'] teste.reverse() print(teste) Behold working in the ideone. And in the repl it.. Also put on the Github for future reference. The…
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answer73
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answer135
viewsA: Use of typedef for pointer
Thus? #include <stdio.h> #include <stdlib.h> struct ponto { int a, b; }; typedef struct ponto * Ponteiro; typedef struct ponto estrutura; int main() { Ponteiro p =…
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answers1944
viewsA: View or temporary table?
The jocose text there is only because there would be many subjects :) In fact they have nothing to do, they are very different mechanisms for very different purposes, with different commitments.…
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answer273
viewsA: Using the switch function in C++
Unable to use strings in the case, there can only use simple types such as numbers and individual characters (which are no longer numbers). If you need to do it with string have to use if and…
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answers16608
viewsA: What is the difference between MER (Relationship Entity Model) and DER (Relationship Entity Diagram)?
The MER is what you want to do effectively, is the tool to create data models and their relationships, in general that will then be produced in a relational database. The ERI is just a visual way to…
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answer385
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answer72
viewsA: Condition of a query with an under-consumption
This business of updating the latest records does not work very well, is fragile, can give the expected result once and not another. But if you’re going to insist on it do it simply, don’t use…
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answers1012
viewsA: Duplicate keys
When creating the index you should use this clause: WHERE email IS NOT NULL; I put in the Github for future reference.…
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answer14836
viewsA: How to calculate the sum of each row of a matrix in C?
It takes a array to store the lines. It should be the same size as the number of input lines. Don’t forget to reset the data. I did this with memset(). And then sum equal to the total, only on each…
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answers410
viewsA: Private class in Javascript
Power, can. Do what you want? No undesirable effects? Only you can answer this. If you do everything correctly you can do it. If you’re not sure about this and you don’t do anything different, don’t…
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answers295
viewsA: What’s the difference between using Return and print in this recursive function that calculates the sum of numbers?
First, this code works better iteratively and not recursively. Let’s learn recursion with problems that need to be recursive and learn better. A basic error is that it is not returning the recursion…
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answers1126
viewsA: What kind of data (double, float) should I use when representing a temperature?
There is no specific type suitable, for this case some can be used. In fact, if you’re going to create types to handle these temperatures and you’re going to use a sophisticated infrastructure to…
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answers103
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answers482
viewsA: Error comparing strings
The most performative and idiomatic form would be direct use with char both in the letter you want to search for and in the individual access. This is easier with o for` which automatically scans a…
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answer675
viewsA: Which is the most up-to-date version of the C language and which compiler works best?
Today C18 is the most updated specification where GCC 8 and Clang 6 are supporting, but in essence changes nothing important compared to C11. Few people use C11, the previous specification that…
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answer991
viewsA: How to join two vectors in another that does not have repeated values?
There are several ways to do this and easier, but following the requested algorithm, making it smarter and simpler, without changing too much would be this: using static System.Console; namespace…
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answer231
viewsA: What is a Bootstrapping?
Bootstrapping is the action of starting something on its own. Even this term in programming has at least two contexts. When something starts and prepares the environment for what it matters to run…
terminologyanswered Maniero 444,682 -
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answers311
viewsA: Return Value ID C# Npgsqlcommand
That? using (var conn = new NpgsqlConnection(conn) { conn.Open(); using (var cmd = new NpgsqlCommand("INSERT INTO public.localpo(NOME) VALUES (:nome)", conn)) { cmd.Parameters.Add(new…
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answers89
viewsA: OFFSET next to COUNT(*) returns nothing?
No "returns". COUNT() results in the total amount of items he has found that satisfy the established query. How much information results? One. Just the total amount, a single amount. When you say…
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answers132
viewsA: SHA512 hexadecimal return
That? public static string HashedString(string text) { var sha512 = new SHA512Managed(); byte[] hash = sha512.ComputeHash(Encoding.UTF8.GetBytes(text)); var result = new StringBuilder(); foreach…
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answer605
viewsA: "Printf not declared in this Scope" even with the use of #include <stdio. h>
Within stdio exists printf() but not prinft(), as the error determines. When you see an error message read it carefully.
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answers165
viewsA: How to take the first character of a String and make it uppercase by storing it in a variable?
var c = char.ToUpper(texto[0]); I put in the Github for future reference. Documentation. But before using this, delete all your code and start again, this time write a code without goto and with the…
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answers1449
viewsA: Undefined object reference for an object instance in array
Each member of the array must have an instance of the class DadosFilme and is not creating this instance. You would have to do this before you can use each item: dados[i] = new DadosFilme(); The…
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answer83
viewsA: Comparison going wrong
what her reason is? Because this is a way of writing in code, because it is difficult to write otherwise immobilely in a current way. But it’s just like it’s in the code, in the document it’s not…
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answers148
viewsA: How do you model a role in object orientation?
Very simply: class Pessoa { string Nome; } class Cliente { Pessoa pessoa; decimal credito; } class Faturamento { Venda(Cliente cliente) => Write(cliente.pessoa.Nome); } If you wish people to be…
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answer69
viewsA: The function returns Undefined. What’s wrong?
Of course, the code is returning nothing. The function makes a calculation in there and abandons this resulting. A return returns nothing, um return <expressão> returns the expression.…
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answers341
viewsA: Why am I calling the subclass method?
The polymorphism is just the opposite of what you think it is. It indicates that the concrete object is what determines what will be executed and not the type that is waiting. Without the…
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answer826
viewsA: How to configure the amount of exponent numbers in scientific notation in C++
Everything is ok in compiler that works according to the specification. #include <stdio.h> int main() { float num; scanf("%f", &num); printf("%.4e\n", num); } Behold working in the ideone.…
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answer1612
viewsA: The first 100 prime numbers
There are several problems in this logic that I don’t even know where to start. Besides the code is too complex. Divide the problem to understand easier. The basic logic is to count to 99 (as it was…
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answer728
viewsA: What is and what is the explanation for type-safe in C#?
I will give a summary to laypeople, I will not do here a monograph on type theory. Type security is the quality of doing operations on data only when the operation makes sense. Spoken languages type…
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answers183
viewsA: How to implement this while not from Python in C?
There is no while not, there is the operator not which is independent of while. If you just want to apply the not you have to exchange this operator who uses the English word for the symbol ! which…
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answers679
viewsA: What determines a variable as a Python array?
List is the name Python gives to what is known as array. In fact the array pure as we know Python doesn’t. It is a data structure that are placed in sequence and that each element is accessed in…
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answers306
viewsA: Understanding the exercise of the book Use the Java Head
return 1; //Sempre retornará 1, aqui entendi Not always, will return only if index is less than 7. return 0; //Não achei o porque do return 0 neste ponto He will execute whenever index is not less…
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answers1335
viewsA: What is the advantage of dependency injection in relation to an object instance?
In essence the advantage is flexibility. Understand that DI (Dependency Injection) is a pompous name for something very simple. I’ve talked about it in a couple of questions and my answer. Just…
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answer658
viewsA: Is the null character 0 automatically placed at the end of the string or not because I limited the scanf?
You can test on your own: #include <stdio.h> int main(void) { char nomeSobrenome[40]; printf("Insira seu nome e seu sobrenome:\n"); scanf("%[A-Z a-z 0-9 !-_]s", nomeSobrenome); printf("%s\n",…