c# - How to get number of characters from left side of a string

Get number of characters from String left side
The String represents text as a sequence of UTF-16 code units. The String is a sequential collection of characters that is used to represent text. The String is a sequential collection of System.Char objects.

The following .net c# tutorial code demonstrates how we can get a number of characters from the left side of a String instance. So, in this .net c# tutorial code we will get a specified number of characters from the beginning of a String object. Here we will use String Substring() method to do this.

The String Substring() method retrieves a substring from this instance. The String Substring(Int32, Int32) method overload retrieves a substring from this instance where the substring starts at a specified character position and has a specified length.

So using Substring(int startIndex, int length) method overload we can get a specified number of characters from a String left side. To get that we have to pass the 0 for the startIndex parameter value and a specified number for the length parameter value. Then the method returns the specified number of characters from the String left side.

The String Substring(int startIndex, int length) method throws ArgumentOutOfRangeException if the startIndex plus length indicates a position that is not within this instance. The method also throws this exception if the startIndex or length parameter value is less than zero.
string-left.aspx

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

<!DOCTYPE html>  
<script runat="server">
    protected void Button1_Click(object sender, System.EventArgs e)  
    {
        //this section create a string variable.
        string plants = "Buffalo Weed. Buckeye. Blackhaw. False Boxwood";

        Label1.Text = "string of plants..................<br />";
        Label1.Text += plants + "<br />";

        //this line get left most 7 letters from string
        string leftSubString = plants.Substring(0, 7);

        string left13Characters = plants.Substring(0, 13);

        Label1.Text += "<br />left most 7 characters from plants string........<br />";
        Label1.Text += leftSubString;

        Label1.Text += "<br /><br />left most 13 characters from plants string........<br />";
        Label1.Text += left13Characters;
    }  
</script>  
  
<html xmlns="http://www.w3.org/1999/xhtml">  
<head id="Head1" runat="server">  
    <title>c# example - string left</title>  
</head>  
<body>  
    <form id="form1" runat="server">  
    <div>  
        <h2 style="color:MidnightBlue; font-style:italic;">  
            c# example - string left
        </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 left"  
            OnClick="Button1_Click"
            Height="40"  
            Font-Bold="true"  
            />  
    </div>  
    </form>  
</body>  
</html>
More c# examples