Home / Questions

All Questions

Martin Hope
Ariel Montes
Asked: 2021-12-19 03:30:57 +0800 CST
  • 15

In Python I can append values ​​to a list using the append() function among other things, but with tuples this all changes and the way they are handled is different. Its structure seems very similar to that of a list, and I would like to know its usefulness or purpose.

Tuples in Python have this structure:

a = (1,2,3,4)

While the lists is another:

b = [1,2,3,4]

I would be grateful if someone could explain to me why tuples are necessary in Python and in what cases they should be used.

python
Martin Hope
Popularfan
Asked: 2020-07-20 03:09:39 +0800 CST
  • 15

I have this element:

<input id="Nombre" class="clase1 clase2 clase3" type="text" />

in JavaScript I can get the element like this:

var item = document.getElementById("Nombre");

Now how can I know if the element "item" contains the class "clase2"

That is, how can I know if an element has a class?

javascript
Martin Hope
Antonio Ruiz
Asked: 2020-07-03 03:47:39 +0800 CST
  • 15

This is the code, I want that when clicking on Do you want to book? the "calendario_reservation" div is displayed, but something is wrong:

activar_reserva();

function activar_reserva(){
    if(document.getElementById('activar_reserva').checked){ 
        document.getElementById('calendario_reserva').style.display = "unset"; 
    }else{ 
        document.getElementById('calendario_reserva').style.display = "none"; 
    }
}
<form action="#" method="post">
  <input type="checkbox" id="activar_reserva" onclick="activar_reserva();">
  <label>¿Quieres reservar?</label>

  <div class="" id="calendario_reserva">
  AQUI UN CALENDARIO PARA SELECCIONAR LA FECHA.
  </div>

  <br/>
  <button type="submit" name="action" value="contestar" class="form-control fondo2 color1" style="margin-top:10px;">Enviar</button>

</form>

https://jsfiddle.net/ogdbt09v/

javascript
Martin Hope
César
Asked: 2020-12-03 08:01:11 +0800 CST
  • 16

In forms, programmers are using typesHTML5 typed inputs ( ). For example, the following case requires the entry of a number between 13 and 16 digits:

<input type="text" pattern="[0-9]{13,16}" title="A credit card number" />

enter image description here

As can be seen in the image, the browser (Chrome in this case), shows a validation which I want to avoid since we want to pass this and other validations to the server side and display customized messages.

Is there a way to get rid of these browser-generated validation messages without having to manually edit each inputform?

validación
Martin Hope
jachguate
Asked: 2020-11-03 07:23:51 +0800 CST
  • 16

I am making an application in which I would like to receive the temperature through an Arduino. I think using Sockets is a great way to communicate, but I have no idea how to use Sockets in an Android application made with Delphi.

Is it different from how it is used in Delphi compiled for Windows?

android
Prev
Next