String.Replace ignoring case

Question

I have a string called \"hello world\"

I need to replace the word \"world\" to \"csharp\"

for this I use:

string.Replace(\"World\", \"csharp\         


        

Answer 1

Using @Georgy Batalov solution I had a problem when using the following example

string original = "blah,DC=bleh,DC=blih,DC=bloh,DC=com"; string replaced = original.ReplaceIgnoreCase(",DC=", ".")

Below is how I rewrote his extension

public static string ReplaceIgnoreCase(this string source, string oldVale, 
string newVale)
    {
        if (source.IsNullOrEmpty() || oldVale.IsNullOrEmpty())
            return source;

        var stringBuilder = new StringBuilder();
        string result = source;

        int index = result.IndexOf(oldVale, StringComparison.InvariantCultureIgnoreCase);
        bool initialRun = true;

        while (index >= 0)
        {
            string substr = result.Substring(0, index);
            substr = substr + newVale;
            result = result.Remove(0, index);
            result = result.Remove(0, oldVale.Length);

            stringBuilder.Append(substr);

            index = result.IndexOf(oldVale, StringComparison.InvariantCultureIgnoreCase);
        }

        if (result.Length > 0)
        {
            stringBuilder.Append(result);
        }

        return stringBuilder.ToString();
    }