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Whats the differenct between "items.add ()" and "Items.Add(New ListItem())"

Hi!

I am really struggeling to understand when I need and when I can ignore making new instances of an object.

In the first code example below, example A, I, use the Items.Add(New ListItem()), but I get the same expected result if I let it out. Why?

The only difference between Example A and B are these rows

A: listbox1.Items.Add(New ListItem("Carbon"))
listbox1.Items.Add(New ListItem("Oxygen"))

B: Listbox1.Items.Add("Carbon")
Listbox1.Items.Add("Oxygen")

However, if I try to add both a text and a value, I, can only do so by using

ListBox1.Items.Add(New ListItem("Carbon", "C"))
ListBox1.Items.Add(New ListItem("Oxygen", "O"))

This code will not work

ListBox1.Items.Add("Carbon", "C")
ListBox1.Items.Add("Oxygen", "O")

I will be greatful for an explaination of this individual case but also for rules of thumbs that I can use. I have a lot of books but maybe there are better ones, that some one can give me a recommendation of.

Example A

 <%@ Page Language="VB" AutoEventWireup="True" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >

<head id="Head1" runat="server">
    <title> CheckBoxList Constructor Example </title>
<script runat="server">

    Protected Sub Button1_Click(ByVal sender As System.Object, _
      ByVal e As System.EventArgs) Handles Button1.Click
        listbox1.Items.Add(New ListItem("Carbon"))
        listbox1.Items.Add(New ListItem("Oxygen"))
    End Sub

   </script>

</head>

<body>

   <form id="form1" runat="server">

      <h3> CheckBoxList Constructor Example </h3>
       Select items from the CheckBoxList.

       <asp:ListBox ID="listbox1" runat="server"></asp:ListBox>
     
      <br /><br />

    

      <br /><br />
       <asp:Button ID="Button1" runat="server" Text="Button" />

   </form>

</body>

</html>

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Example B

<%@ Page Language="VB" AutoEventWireup="True" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >

<head id="Head1" runat="server">
    <title> CheckBoxList Constructor Example </title>
<script runat="server">

    Protected Sub Button1_Click(ByVal sender As System.Object, _
      ByVal e As System.EventArgs) Handles Button1.Click
        Listbox1.Items.Add("Carbon")
        Listbox1.Items.Add("Oxygen")
    End Sub

   </script>

</head>

<body>

   <form id="form1" runat="server">

      <h3> CheckBoxList Constructor Example </h3>
       Select items from the CheckBoxList.

       <asp:ListBox ID="Listbox1" runat="server"></asp:ListBox>
     
      <br /><br />

    

      <br /><br />
       <asp:Button ID="Button1" runat="server" Text="Button" />

   </form>

</body>

</html>

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kaufmed

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marcgu

ASKER

This answer, including the links, will definately bring me forward. Thanks

Whats the differenct between &quot;items.add ()&quot; and &quot;Items.Add(New ListItem())&quot;

Whats the differenct between "items.add ()" and "Items.Add(New ListItem())"