how to extract formating part from a string

Question

How does one extract only the formatting part from a string. For example: if I have a string = "Warning: the error {0} has occurred. {1, 9} module has {2:0%} done." I would like to extract {0}, {1,9} and {2:0%} out into a sting array. Is there a regular expression or something that can be done other than my way of looping the string with Substring indexof '{' and '}' alternately?

Answer 1

Will some variant of "\{[^}]+\}" not work? Run it through finding the matches and substring'ing out from start to end of the match.

Answer 2

new Regex(@"\{[0-9:,% .]+\}");

You may have to tweak/tune it to account for any additional formatting options that you haven't provided in your example.

Answer 3

In Java, the Matcher class takes a regex and will return all matching sub-strings.

For example:

String str = "Warning: the error {0} has occurred. {1, 9} module has {2:0%} done.";

Matcher matcher = pattern.matcher( "{.*}");
while (matcher.find()){
    String matched = matcher.group()
    \\do whatever you want with matched
}

Answer 4

The following code is different from other answers in that it uses non-greedy matching (".*?"):

    private static void Main(string[] args) {
        const string input = "Warning: the error {0} has occurred. {1, 9} module has {2:0%} done.";
        const string pattern = "{.*?}"; // NOTE: "?" is required here (non-greedy matching).
        var formattingParts = Regex.Matches(input, pattern).Cast<Match>().Where(item => item.Success).Select(item => item.Groups[0].Value);
        foreach (var part in formattingParts) {
            Console.WriteLine(part);
        }
    }