Posts by Maniero • 444,682 points
6,921 posts
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viewsA: Values returned in comparison of strings in C
In accordance with the documentation returns negative if the first argument comes before the second by comparing the lexicography (alphabetical order) of the text, and will receive a positive…
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answers3588
viewsA: How not to print the line break using the console.log
It is not possible, not least because this was created to help the debug of your application, so no special formatting is required. This function does not print on screen. If you still want to do…
javascriptanswered Maniero 444,682 -
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viewsA: How much can the access cost of an unodered_map hinder the performance of a game?
Difficult to answer without a context, but it’s highly unlikely that this will affect significantly, at least not for him. Of course the function that calculates the code hash used to map, the…
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answers701
viewsA: How do I use %d or %c... in Cout instruction?
You must study stream of io and their handlers. Example: #include <iostream> using namespace std; int main() { auto x = 65; cout << "i make " << x << " program\n"; cout…
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answer302
viewsQ: What is the Recyclerview?
I saw the class at documentation of Andorid, but I did not understand its functionality, where it should be used and with what purpose. The name referred me to something that doesn’t seem to be what…
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answer439
viewsA: Do I need a macOS computer to program Swift 4 and Objc?
In no way can they be used on multiple platforms. These languages are not "Apple’s", they are only maintained by Apple. Of course, whether you want to do something for Macos or iOS complicates a…
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answers218
viewsA: See how native functions were written - Python
All Python source code (standard implementation) is on Github and can be consulted. The role max().…
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answers271
viewsA: Javascript equivalent of "Date.now()" in C#?
In recent versions you can use so: using System; using static System.Console; public class Program { public static void Main() { WriteLine(DateTimeOffset.UtcNow.ToUnixTimeMilliseconds()); } } Behold…
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answers381
viewsA: Average input data algorithm
There are several problems in the code and this is mainly caused because it is a complete mess. I only understood after rewriting everything: import java.util.Scanner; public class Main { public…
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answer180
viewsA: Why does Floattostr exist if Delphi does not possess the Float data type?
There are programmers who have trouble naming things. Actually it’s kind of normal among people in general, there’s even a quote that the two hardest things in computing is to invalidate cache and…
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answers141
viewsA: Is there performance gain using . replace() instead of . put() in a Map?
replace() is more efficient in cases where there is no key being used in it. It can only replace a value from an existing key, executes nothing if it does not have the key. Already the put() will…
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answers299
viewsA: How to get the amount of "true"?
This LINQ business to take data from the database doesn’t work as well as people imagine and brings several complications when it comes out of the trivial, and doesn’t even need to go very far. This…
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viewsA: Use string to reference variable
First of all this syntax is not C#. It is always possible to build a sophisticated mechanism that allows this. But for what? One of the ways is to use reflection, but almost 100% of the cases that…
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answer74
viewsA: Where should I instantiate the objects?
They are inside folders with established nomenclatures. The class name must be identical to the file name. No, object-oriented programming has nothing to do with it, and it doesn’t preach anything…
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answer128
viewsA: Analogy between POO and database
If so, then what would be the analogue of a BD interface? Nothingness. And what would be, in POO, the analogue of a bridge table? There is nothing special about it. The most that can occur, but…
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answer120
viewsA: Using a pointer can make my code faster?
No, that doesn’t make sense even because the index of a vector is a pointer. Of course there may be some situation that you make wrong and can make a difference, but it is circumstantial. See:…
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answer112
viewsA: How to print a hexadecimal value in high box?
It is only user the uppercase: #include <iostream> using namespace std; int main(void) { int n; cin >> n; cout << uppercase << hex << n << endl; } Behold working…
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answer151
viewsQ: Is there any technical reason for the Observer pattern or similarities not to be used independently of the observed object?
We often use things we don’t even think about because it’s like this. I don’t like to put mechanism bumpers on object that is of specific domain. If I have a screen control or a client who has some…
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answer1903
viewsA: Break and Continue on Switch
The switch in itself does not accept a continue, but accepts break, which can be a little confusing because the loops repeat while, do ... while, for, for : accept both control flow command that…
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answer1137
viewsA: How do auto increment in Mysql without declaring columns in INSERT?
Since you are using a positional syntax with all columns you have to send values to all columns. And since you do not want to send to the first column, send a null. Since it has an automatic default…
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answer41
viewsA: User connection location in Mysql or Mariadb
Users work differently. A user must be registered according to where they can access. Although it is the same person when he accesses from one place or another the privilege should, in theory, be…
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answer111
viewsA: What is type reference?
Bad translation (I believe). You’re talking about types by reference. I talk about it in What’s the difference between Struct and Class?. These are types that are naturally already objects pointed…
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viewsA: Dynamic allocation with a void function
Yes, it is absurd to do this. Even to learn it does not seem appropriate, because it is learning to do something wrong that should not be done. It’s even easier to do it the right way. And the fact…
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answer1651
viewsA: Store positives in one vector and negatives in another
It’s much simpler than this: #include <stdio.h> int main(void) { int pos[3], neg[3], posCount = 0, negCount = 0; for (int i = 0; i < 3; i++) { int valor; printf("Informe um valor: ");…
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answer71
viewsA: Using good practice or the right way to store an ID
It is not very visible. It is sufficiently visible. If your system allows something wrong to be done just because someone knows what the ID is, then your system is very flawed. Fix it, don’t try to…
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answer256
viewsA: What is the purpose of a TT extension file?
It’s a file of template used by Visual Studio (T4). It is used to create snippets of code and other forms that give a basis of what you want to do. It was used a little more for code generation, but…
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answer354
viewsA: How to update the database with SELECT Sum
Thus? UPDATE usuarios SET total = dinheiro + depositado WHERE id = 1 I put in the Github for future reference. Understand the columns as variables. You don’t have to do anything crazy to get your…
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viewsA: Make an "Update" with sum of a number that is as character
It’s very simple, turn the column into a numeric type. Use text for descriptive columns, even if you only have numeric digits in it. And use numeric columns when you need to do accounts, like this.…
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answer150
viewsA: Does using or not block definition in simple "if" influence application performance?
The use of more lines as in the examples above, will influence the performance of the application? In Delphi does not influence anything in this case reported. Of course, a poorly written source…
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answers753
viewsA: What does the exclamation mark mean after a guy’s name?
Indicates that the type can be null. In Kotlin the types cannot be null by default. But in Java they can, at least the types by reference. Then you need to have a type that allows you to…
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answers74
viewsA: Questions about ID in the register of a web system
You’re the one who needs to answer the question, like every UX question. Do you need to show this ID for any reason? Does the user need to be aware of this? Maybe to get some support? You can…
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answer608
viewsA: What does the class name mean in super(). __init__()?
From what I understand ListaUnica expects a type as a parameter to do some sort of check if the list is always receiving an element of the same type. In fact the code is bad and does not meet this…
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answer177
viewsA: Inheritance class: error TS2554: Expected 5 Arguments, but got 0
In the daughter class is calling the super(). How many arguments are you passing on it? Zero!. In the mother class the constructor has 5 parameters. If it has these parameters, you need to pass all…
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viewsA: Char pointer in printf() does not work
There are several errors in this code. You are passing a array by reference, of which array is already a reference. Whether to use a variable to walk by array, use it instead of accessing the direct…
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answers390
viewsA: Float with PHP precision
In fact it lacks a function to truncate in PHP, they made a in the OS: function truncate($val, $f = "0") { if(($p = strpos($val, '.')) !== false) { $val = floatval(substr($val, 0, $p + 1 + $f)); }…
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viewsA: Using interfaces for domain classes
Creating by creating for no reason has no advantage. In everything you do, everything you do, until you put a blank space in the code, you need to find a motivation. That’s why I always tell people…
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viewsA: Open and close the code or use variable?
The first involves more processing, is a PHP code being interpreted and processed to generate a text that will be sent to the server (possibly). The second is already considered the text to be sent…
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answer851
viewsA: Array counter with while in JS
What you want is not to count the items, because it is difficult to tell something without knowing how many you have, and knowing how many you have does not need to count. To tell something you…
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answers354
viewsA: Close() method in Try and catch blocks is necessary?
First you need to know if all the code is correct. When it comes to this kind of thing I see a lot of things wrong. Second, you need to see the context, because you might not want to close, so you…
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answer75
viewsA: Sonarlint x Java GC, cancel or not object at the end of the execution?
This type of utility does not understand the context of the application. If you use this and you don’t understand what you’re doing, you’ll start screwing up the application as much as you will. In…
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viewsA: How to ignore accents in an SQL query?
I’d go that way: How to make "case-insensitive" comparisons in Sqlite?. Is the simple. Note that some implementations of Sqlite already have a way to deal with this, but they no longer have the…
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viewsA: Is it worth putting two foreign keys on a table?
The description should use yes, but not right. Need the performance? One thing I see a lot in reports is not need, but depends on the case. The more indexes you place the slower it gets to update…
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answer178
viewsA: How many classes can we have in one package?
As many as you want. Even if it has a theoretical limit it is much larger than the practical. What exists is only a recommendation for one class per source file. And this has nothing to do with…
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answers16658
viewsA: How to round up with Python?
Using pure math whenever you want to round a number up add an entire unit of the value whatever the rounding is done and take the whole part, this will ensure that it will always fall to the next…
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answers519
viewsA: How does C# run on other platforms?
But what about Linux? I know that without . NET Core installed it won’t be able to run an application natively from . NET, but this requires its installation on the machine. This is not true. The .…
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answer278
viewsA: .NET Core and Mono: application development for Linux
The answer doesn’t make much sense anymore, see The . NET Framework is dead?. Mono’s fate is the same. I prefer the . NET Core that already has a larger community and Microsoft’s priority support.…
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viewsA: How does Python overload polymorphism work?
It doesn’t. It doesn’t make sense in a dynamic typing language. The overload depends on the number of parameters and their types to form a signature. Python only has the name in the signing, then it…
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answer131
viewsA: Comparison in "if" does not fall where it should
There are two problems in the code. 1) is using & in something that is already a memory address. When you have a array, you already have what the scanf() wait. 2) You’re comparing strings as if…
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viewsA: Alternatives to Microsoft Lightswitch
The ideal is not to use anything of this kind of thing. All are bad. But if you want to insist and get into another roll have some alternatives: Devforce XAF Powerapps (it’s not the same, but it…