C#

private string insertChars(string str, char insertChar, int[] insertIndexes)
{
    StringBuilder b = new StringBuilder(str.Length + insertIndexes.Length);
    int count = 0;

    for (int i = 0; i != str.Length;i++)
    {
        if (i == insertIndexes[count])
        {
            b.Append(insertChar);

            if (++count==insertIndexes.Length)
            {
                b.Append(str.Substring(i,str.Length-i));
                break;
            }
        }

        b.Append(str[i]);
    }

    return b.ToString();
}

string oneSpace = " ";
string twoSpaces = "  ";
string str = "You  left out       any  multiple    spaces in your            example";
string newStr = str.Replace(twoSpaces,oneSpace);

string s="whatever with many spaces";
do {
    int len=s.Length;
    s=s.Replace(twoSpaces, oneSpace);
} while (s.Length<len);

string test = "this  string   has    multiple    spaces      .";
StringBuilder sb = new StringBuilder(test);
int l1 = sb.Length;
int l2 = l1 +1;
while (l1 != l2)
{
    l1 = sb.Length;
    sb.Replace("  ", " ");
    l2 = sb.Length;
}
string result = sb.ToString();

if ( args.Length > 0 )
{
    System.Console.Write 
    ( 
        "<" + 
        PIEBALD.Lib.LibStr.Compress ( args [ 0 ] , " \b" , " " , "'" , "\\" ) 
        + ">" 
    ) ;
}

/**************************************************************************************************************/
/*  Compress sequences of "trash" characters down to one                                                      */

        public static string
        Compress
        (
            string subject      ,
            string trash        ,
            string replacements ,
            string quotes       ,
            string escapes
        )
        {
            System.Text.StringBuilder result = new System.Text.StringBuilder ( subject.Length ) ;

            char prevch = '\0' ;
            int  index  = 0    ;
            int  quo    = -1   ;
            int  quoon  = -1   ;
            int  escon  = -1   ;

            if ( quotes == null )
            {
                quotes = "" ;
            }

            if ( escapes == null )
            {
                escapes = "" ;
            }

            while ( index < subject.Length )
            {
                if ( ( escon = escapes.IndexOf ( prevch ) ) != -1 )
                {
                    quoon = -1 ;
                }
                else
                {
                    quoon = quotes.IndexOf ( subject [ index ] ) ;
                }

                if ( quoon != -1 )
                {
                    if ( quo == -1 )
                    {
                        quo = quoon ;
                    }
                    else
                    {
                        if ( quo == quoon )
                        {
                            quo = -1 ;
                        }
                    }
                }

                prevch = subject [ index ] ;

                if ( ( quo == -1 ) && ( trash.IndexOf ( subject [ index ] ) != -1 ) )
                {
                    if ( ( index == subject.Length-1 ) || ( trash.IndexOf ( subject [ index+1 ] ) == -1 ) )
                    {
                        result.Append ( replacements [ 0 ] ) ;
                    }
                    else
                    {
                        if ( replacements.Length > 1 )
                        {
                            result.Append ( replacements [ 1 ] ) ;
                        }
                    }

                    index++ ;
                }
                else
                {
                    result.Append ( subject [ index++ ] ) ;
                }
            }

            return ( result.ToString() ) ;
        }

Rick van Woudenberg wrote:

treeView1.Nodes.Add(new TreeNode(r["res_lastname"].ToString()));
treeView1.Nodes.Add(new TreeNode(r["res_firstname"].ToString()));