Remove text in-between delimiters in a string (using a regex?)
.net, algorithm, c#, regex, string
Solution
Simple regex would be:
string input = "Give [Me Some] Purple (And More) Elephants";
string regex = "(\\[.*\\])|(\".*\")|('.*')|(\\(.*\\))";
string output = Regex.Replace(input, regex, "");
As for doing it a custom way where you want to build up the regex you would just need to build up the parts:
('.*') // example of the single quote check
Then have each individual regex part concatenated with an OR (the | in regex) as in my original example. Once you have your regex string built just run it once. The key is to get the regex into a single check because performing a many regex matches on one item and then iterating through a lot of items will probably see a significant decrease in performance.
In my first example that would take the place of the following line:
string input = "Give [Me Some] Purple (And More) Elephants";
string regex = "Your built up regex here";
string sOutput = Regex.Replace(input, regex, "");
I am sure someone will post a cool linq expression to build the regex based on an array of delimiter objects to match or something.
Problem
Consider the requirement to find a matched pair of set of characters, and remove any characters between them, as well as those characters/delimiters. Here are the sets of delimiters: ``` [] square brackets () parentheses "" double quotes '' single quotes ``` Here are some examples of strings that should match: ``` Given: Results In: ------------------------------------------- Hello "some" World Hello World Give [Me Some] Purple Give Purple Have Fifteen (Lunch Today) Have Fifteen Have 'a good'day Have day ``` And some examples of strings that should not match: ``` Does Not Match: ------------------ Hello "world Brown]co[w Cheese'factory ``` If the given string doesn't contain a matching set of delimiters, it isn't modified. The input string may have many matching pairs of delimiters. If a set of 2 delimiters are overlapping (i.e. `he[llo "worl]d"`), that'd be an edge case that we can ignore here. The algorithm would look something like this: ``` string myInput = "Give [Me Some] Purple (And More) Elephants"; string pattern; //some pattern string output = Regex.Replace(myInput, pattern, string.Empty); ``` Question: How would you achieve this with C#? I am leaning towards a regex. Bonus: Are there easy ways of matching those start and end delimiters in constants or in a list of some kind? The solution I am looking for would be easy to change the delimiters in case the business analysts come up with new sets of delimiters.