Generic List ForEach() method in asp.net c#

Generic List ForEach() Method
.Net framework generic list ForEach() method allow us to perform the specified action on each element of the List<T>. the ForEach() method exists in under System.Collections.Generic namespace. this method need to pass a parameter named 'action'. this 'action' parameter type is System.Action<T>. the Action<T> delegate to perform on each element of the List<T>.

if the parameter 'action' is null the method throw an exception named ArgumentNullException. in the bellow example we created a String type generic list. by using the ForEach() method we insert a * character at the beginning of each element of generic list.

the following asp.net c# example code demonstrate us how can we perform a specified action on each element of a generic list in an asp.net application.
GenericListForEachMethod.aspx

<%@ Page Language="C#" AutoEventWireup="true" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
    protected void Button1_Click(object sender, System.EventArgs e)
    {
        List<string> colors = new List<string>() {"Lavender","LawnGreen","SeaGreen"};
        colors.Add("LightGoldenRodYellow");
        colors.Add("ForestGreen");

        Label1.Text = "List Elements....<br />";
        foreach (string color in colors)
        {
            Label1.Text += "<br />" + color;
        }

        Label1.Text += "<br /><br />After Call ForEach() Method List Elements are.....<br />";
        
        colors.ForEach(delegate (String s)
        {
            Label1.Text +="<br />" + s.ToLower().Insert(0,"*");
        });
    }
</script>

<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
    <title>Generic List ForEach() - How to perform the specified action on each element of the List</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <h2 style="color:Olive; font-style:italic;">
            System.Collections.Generic.List ForEach() Method
            <br /> How to perform the specified action on each element of the List
        </h2>
        <hr width="575" align="left" color="ForestGreen" />
        <asp:Label
             ID="Label1"
             runat="server"
             ForeColor="DarkOrchid"
             Font-Size="Large"
             Font-Names="Courier New"
             >
        </asp:Label>
        <br /><br />
        <asp:Button 
            ID="Button1"
            runat="server"
            OnClick="Button1_Click"
            Text="Test Generic List ForEach() Method"
            Height="45"
            Font-Bold="true"
            ForeColor="DodgerBlue"
            />
    </div>
    </form>
</body>
</html>
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