C# Ignore Case and Check if String contains Substring

To ignore case and check if specified substring value is present in the string str, use String.Contains(String, StringComparison) method.

Prepare StringComparison object comp with StringComparison.OrdinalIgnoreCase. Call Contains method on the string str and pass the substring value, and string comparison comp objects as arguments.


If the substring is present inside the string, of course ignoring the case, then String.Contains() method returns True, else, it returns False.

C# Program

using System;
class Example {
    static void Main(string[] args) {
        String str = "abcdefgh";
        String value = "CD";
        StringComparison comp = StringComparison.OrdinalIgnoreCase;
        Boolean result = str.Contains(value, comp);
        Console.WriteLine($"Does string contain specified substring? {result}");


Does string contain specified substring? True


In this C# Tutorial, we learned how to check if specified substring is present in a given string while ignoring the case during string comparison.