Question

I am wondering what would be the best way to specify an array of characters like,

{
}
[
]

and then check a string for these and if they are there, to completely remove them.

        if (compiler.Parser.GetErrors().Count == 0)
        {
            AstNode root = compiler.Parse(phrase.ToLower());
            if (compiler.Parser.GetErrors().Count == 0)
            {
                try
                {
                    fTextSearch = SearchGrammar.ConvertQuery(root, SearchGrammar.TermType.Inflectional);
                }
                catch
                {
                    fTextSearch = phrase;
                }
            }
            else
            {
                fTextSearch = phrase;
            }
        }
        else
        {
            fTextSearch = phrase;
        }

        string[] brackets = brackets = new string[]
        {
            "{",
            "}",
            "[",
            "]"
        };

        string[] errorChars = errorChars = new string[]
        {
            "'",
            "&"
        };

        StringBuilder sb = new StringBuilder();

        string[] splitString = fTextSearch.Split(errorChars, StringSplitOptions.None);

        int numNewCharactersAdded = 0;
        foreach (string itm in splitString)
        {
            sb.Append(itm); //append string
            if (fTextSearch.Length > (sb.Length - numNewCharactersAdded))
            {
                sb.Append(fTextSearch[sb.Length - numNewCharactersAdded]); //append splitting character
                sb.Append(fTextSearch[sb.Length - numNewCharactersAdded - 1]); //append it again
                numNewCharactersAdded++;
            }
        }

        string newString = sb.ToString();

Answer 1

A regular expression can do this far more easily:

var result = Regex.Replace(input, @"[[\]()]", "");

Using a character set ([...]) to match anyone of the characters in it and replace with nothing. Regex.Replace will replace all matches.