Parse out text inside pipe delimeter in string

Question

c# I need help parsing out words inside a pipe character into a list of strings.

"You can cancel free of charge until |720| before check-in. You’ll be charged |407.74USD| if you cancel in the |720| before check-in."

The list of strings should contain two items. 720 and 407.74USD.

Thanks

`string.Split`. Every second entry is likely the one you want. — mjwills, Jan 24 '19 at 23:28
I played with variations and you're right. It will always be an even element in the list. Thanks. — Scott Spiller, Jan 24 '19 at 23:38

score 0 · Accepted Answer · answered Jan 25 '19 at 00:26

private static IEnumerable<string> GetStringsBetweenDelimiters(string str, char delimiter)
{
    int openingIndex = default; //index of the opening delimiter
    int closingIndex = -1; //starts from -1 as otherwise it would not work for string
                           //starting with delimiter

    while (true)
    {
        openingIndex = str.IndexOf(delimiter, closingIndex + 1);
        //it has to be +1'd as otherwise it would return closingIndex
        if (openingIndex < 0) yield break; //No more delimiters
        closingIndex = str.IndexOf(delimiter, openingIndex + 1);
        //+1'd for same reason as above
        if (closingIndex < 0) //No closing delimiter
            throw new InvalidOperationException("The given string has odd number of delimiters.");
        //Might just break as well?

        yield return str.Substring(openingIndex + 1, closingIndex - openingIndex - 1);
    }
}

When called like GetStringsBetweenDelimiters(str, '|'), this method would only return the values between two pipe characters. Advantage of this method over string.Split(delimiter) is that it would not allocate unnecessary substrings that are not in between the pipe characters (You can cancel free of charge until, before check-in. You’ll be charged...), and perhaps a bit simpler to use.

Test:

foreach (string str in GetStringBetweenDelimiters(testStr, '|'))
{
    Console.WriteLine(str);
}

prints

720
407.74USD
720

Parse out text inside pipe delimeter in string

1 Answers1