String starts with letter
The following asp.net c# example code demonstrate us how can we
determine whether a string starts with a letterprogrammaticaly at run
time in an asp.net application. .Net framework's String Class represent text
as a series of Unicodecharacters. String Class has no direct method or
property to determine whether a string begins with a letter (a to z).
First, we need to get the first character of a string object to verify it is a letter or not. String.ElementAt()method allow us to get the character at a specified index position from a string. So, we can get the first character of a stringby calling the ElementAt() method as this way String.ElementAt(0), because string object is zero-based index.
Char.IsLetter(Char) overloaded method indicate whether the specified Unicode character is categorized as a Unicode letter.So, we can determine the previously collected first character of a string is a letter or not by accessing the Char.IsLetter(Char)method.
Finally, we can determine whether string starts with a letter by this way String.ElementAt(0).IsLetter(). If it return'true' then string starts with letter; otherwise string is not starts with letter.
First, we need to get the first character of a string object to verify it is a letter or not. String.ElementAt()method allow us to get the character at a specified index position from a string. So, we can get the first character of a stringby calling the ElementAt() method as this way String.ElementAt(0), because string object is zero-based index.
Char.IsLetter(Char) overloaded method indicate whether the specified Unicode character is categorized as a Unicode letter.So, we can determine the previously collected first character of a string is a letter or not by accessing the Char.IsLetter(Char)method.
Finally, we can determine whether string starts with a letter by this way String.ElementAt(0).IsLetter(). If it return'true' then string starts with letter; otherwise string is not starts with letter.
string-starts-with-letter.aspx
<%@ Page Language="C#" AutoEventWireup="true"%>
<!DOCTYPE html>
<script runat="server">
protected void Button1_Click(object sender, System.EventArgs e)
{
//this section create string variables.
string stringPlants = "1. Swamp Holly 2. Winterberry Holly";
string stringPlants2 = "Horse Cane. Indian Paintbrush";
Label1.Text = "string of plants..................<br />";
Label1.Text += stringPlants;
Label1.Text += "<br />"+stringPlants2;
//this line get string first/begin character
char firstCharacter = stringPlants.ToCharArray().ElementAt(0);
//this line get string first/begin character
char firstCharacter2 = stringPlants2.ToCharArray().ElementAt(0);
//test character is letter or not
Boolean isCharacterLetter = char.IsLetter(firstCharacter);
Boolean isCharacterLetter2 = char.IsLetter(firstCharacter2);
Label1.Text += "<br /><br />stringPlants first character: " + firstCharacter;
Label1.Text += "<br />stringPlants2 first character: " + firstCharacter2;
Label1.Text += "<br /><br />stringPlants starts with letter? " + isCharacterLetter.ToString();
Label1.Text += "<br />stringPlants2 starts with letter? " + isCharacterLetter2.ToString();
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
<title>c# example - string starts with letter</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<h2 style="color:MidnightBlue; font-style:italic;">
c# example - string starts with letter
</h2>
<hr width="550" align="left" color="Gainsboro" />
<asp:Label
ID="Label1"
runat="server"
Font-Size="Large"
>
</asp:Label>
<br /><br />
<asp:Button
ID="Button1"
runat="server"
Text="string starts with letter"
OnClick="Button1_Click"
Height="40"
Font-Bold="true"
/>
</div>
</form>
</body>
</html>
