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Questions[lenguaje-agnóstico]

Martin Hope
abulafia
Asked: 2020-12-14 04:51:30 +0800 CST
  • 11

In a recent question on the site, a meme about certain expressions in a programming language is shown, asking how one of them works.

The meme was the following:

enter image description here

The question was how it worked i -=- 1. However, the one that really caught my attention was the last one: i = ~-idoes this really serve the same purpose as the previous ones, that is, to increase iby 1?

If so how does it work?

lenguaje-agnóstico
Martin Hope
Tux9000
Asked: 2020-07-01 18:50:07 +0800 CST
  • 42

I have a doubt about the existence of the famous NaN , I would like to know, what is it for? What is your "existential meaning"?

So far the only thing I have been able to understand based on things I have seen in books and videos is that in summary it would be a kind of Error indicator in mathematical operations that usually warns us that there is an "invalidity" (such as multiplying a string for an integer); In addition, its data type is numeric and its value is undefined and different from any other value.

I am right? is it used for something else?

I add a couple of quotes:

NaN means "Not a Number". When a function or mathematical operation in JavaScript cannot return a specific number, it returns the value NaN instead. It is a property of the global object, and a reference to Number.NaN

JavaScriptNotes for Professionals - GoalKicker.com - Pg. 13.

It is a special static numeric property, NaN, which is equivalent to the global NaN, and is equivalent to Not-a-Number. Anytime you try to use a value in a numeric operation that can't be parsed as a number, you'll get a NaN error.

Javascript Cookbook, Shelley Powers - Pg. 56

NaN is short for Not-a-Number and represents an illegal number. It uses the isNaN() function to determine if a number is legal or valid according to the ECMA-262 specification.

JavaScript Step by Step 2ed. Steve Suehring - Pg. 63

The context of the question would be only in terms of its application in JavaScript, since talking about programming in general, arithmetic, computing or other topics would make the question much broader and it would become a bit ambiguous; on the other hand, I understand that the existence of an "Error", "message" or "alert" may be logical for a situation such as the one that can arise when operating irrational numbers or taking mathematical operations out of the mathematical "context", but , how can NaN differ from "typical" Error messages?

lenguaje-agnóstico
Martin Hope
Dev 200
Asked: 2020-04-11 10:05:56 +0800 CST
  • 13

Without taking into consideration a specific programming language, what would be the difference between parameters and arguments in terms of functions?

Also take into account that according to what I understood from the "clean code" book, it is recommended that the fewer arguments (if possible none) that are passed to the function, the more effective it becomes, why?

If you can add an example of both much better :)

lenguaje-agnóstico
Martin Hope
Patricio Nicolas
Asked: 2020-12-17 16:34:05 +0800 CST
  • 13

I would like to know what is the most efficient way to compare the contents of two arrays, to do this in the least amount of time and to use the least amount of resources.

I present this example in Python of how I do it on a daily basis. For this example, there are few elements, it takes very little time, but as we add elements, the times increase exponentially.

If you want to give an example in another welcome language, the idea is to know the logic of how to do it over the language.

Here the example:

#!/usr/bin/python
# -*- coding: utf-8 -*-

arreglo1   = [1,2,3,4,5,6]
arreglo2   = [0,2,4,6,8,10]
repetidos  = []

for x in arreglo1:
    for y in arreglo2:
        if x == y:
            repetidos.append(x)

print "Los Repetidos son"
for z in repetidos:
    print z

The output is: The Repeats are 2 4 6

lenguaje-agnóstico