¿Cómo agregar un separador al final de una lista?

How to add a separator at the end of a list?

Between each item I want to add a separator line, like this: Unfortunately this adds an extra separator line at the end of the list. Is there a simple way to skip this last separator line? Using string.Join negates the need to check for the last item.

One way to do this is to take the first item, and add a separator and an item every time after, such as: def join (iterator, seperator): it = map (str, iterator) seperator = str (seperator) string = next (it, ”) for s in it: string += seperator + s return string

And so, the best way to join an iterable by a separator is to use str.join. If you want to do this manually, then I’d accept the O ( n 2) performance, and write something easy to understand. One way to do this is to take the first item, and add a separator and an item every time after, such as:

As you noticed, the if is checked at each loop although you know that it will be invalidated only on the last loop. A good way to avoid the problem is to treat the first or last element of your list specifically before (or after) entering the loop. Treating the first element separately is much easier.

The Html.DropDownListFor extension method is a strongly typed extension method generates element for the property specified using a lambda expression. Visit docs.microsoft.com to know all the overloads of DropDownListFor method.

The SelectList constructor overload used above takes three arguments: items: An IEnumerable containing the items in the list. In the example above, the list of genres returned by db.Genres. dataValueField: The name of the property in the IEnumerable list that contains the key value. In the example above, GenreId and ArtistId.

The HTML Select Tag. The HTML element (created by the HTML DropDownList helper) is used to display a complete list of values (such as the list of genres). For edit forms, when the current value is known, the select list can display the current value. We saw this previously when we set the selected value to Comedy.