Question

I have a string “Page 1 of 15”.

I need to get the value 15 as this value could be any number between 1 and 100. I’m trying to figure out:

1. If regular expressions are best suited here. Considering string will never change maybe just split the string by spaces? Or a better solution.

2. How to get the value using a regular expression.

Answer 1

Regular expression you can use: Page \d+ of (\d+)

Regex re = new Regex(@"Page \d+ of (\d+)");
string input = "Page 1 of 15";
Match match = re.Match(input);
string pages = match.Groups[1].Value;

Analysis of expression: between ( and ) you capture a group. The \d stands for digit, the + for one or more digits. Note that it is important to be exact, so copy the spaces as well.

The code is a tad verbose, but I figured it’d be better understandable this way. With a split you just need: var pages = input.Split(' ')[3];, looks easier, but is error-prone. The regex is easily extended to grab other parts of the string in one go.