c# - How to compare two strings

String Compare() Method - case sensitive
.Net framework have many methods to properly manipulate string. String.Compare() method allow us to compare two string objects. this method is overloaded for various support such as we can compare strings by ignoring or honoring case, we also can use culture specific information to influence the comparison.

String.Compere(String, String, Boolean) overloaded method allow us to compare two string objects by honoring their case (case sensitive string comparison). first two parameters is two string objects that we want to compare and thirds parameter is a Boolean value name ignoreCase. this Boolean parameter value False specify the method to honor strings case during comparison.

this method return value is a 32 bit signed integer that indicate the relationship between the two string objects. if the return value is less than zero then the first string is less than second string. return value zero means two strings are equals. and the method return value greater than zero indicate the first string (strA) is greater than second string (strB).

in the following example code we uses String.Compare(String, String) method to compare strings by honoring their case. this comparison uses the current culture to obtain culture specific information such as casing rules and the alphabetic order of individual characters.

the following asp.net c# example code demonstrate us a simple way to compare two strings by honoring their case in .net framework.
Compare.aspx

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


<!DOCTYPE html>

<script runat="server">
    protected void page_Load(object sender, System.EventArgs e) {
        if(!this.IsPostBack)
        {
            TextBox1.Text = "apple.";
            TextBox2.Text = "Apple.";
        }
    }
    protected void Button1_Click(object sender, System.EventArgs e) {
        string testString1 = TextBox1.Text.ToString();
        string testString2 = TextBox2.Text.ToString();
        int result = string.Compare(testString1, testString2);
        Label1.Text = "";

        if(result == 0)
        {
            Label1.Text += "Two strings are equal";
        }
        else if(result == -1)
        {
            Label1.Text += "Test String1 is less than Test String2";
        
        }
        else if(result == 1)
        {
            Label1.Text += "Test String1 is greater than Test String2";
        
        }
        
    }
</script>

<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
    <title>How to compare two string (case sensitive)</title>
</head> 
<body>
    <form id="form1" runat="server">
    <div>
        <h2 style="color:Green">asp.net string example: Compare()</h2>
        <asp:Label 
             ID="Label1" 
             runat="server" 
             Font-Size="Large"
             ForeColor="SeaGreen"
             Font-Bold="true"
             Font-Italic="true"
             >
        </asp:Label>
        <br /><br />
        <asp:Label 
             ID="Label2" 
             runat="server" 
             Text="Test String1"
             ForeColor="Red"
             >
        </asp:Label>
        <asp:TextBox 
             ID="TextBox1" 
             runat="server" 
             BackColor="OrangeRed" 
             ForeColor="AliceBlue"
             >
        </asp:TextBox>
        <br />
        <asp:Label 
             ID="Label3" 
             runat="server" 
             Text="Test String2"
             ForeColor="Red"
             >
        </asp:Label>
        <asp:TextBox 
             ID="TextBox2" 
             runat="server" 
             BackColor="OrangeRed" 
             ForeColor="AliceBlue"
             >
        </asp:TextBox>
        <br /><br />
        <asp:Button 
             ID="Button1" 
             runat="server" 
             OnClick="Button1_Click"
             Font-Bold="true"
             Text="Compare"
             ForeColor="Crimson"
             />   
    </div>
    </form>
</body>
</html>
More c# examples