Question

I have a list of strings which contain 4 items:

Orange
Lemon
Pepper
Tomato

Also, I have a String str which has a sentence:

Today, I ate a tomato and an orange.

1) How can I check that str has some keywords from list? without considering upper or lower case letters, basically capturing anything that matches?

I tried this but it doesn’t work because it will look for the same words. list.Contains(str)

Also Dim result As String() = list.FindAll(str, Function(s) s.ToLower().Contains(str)) but also didn’t work.

2) What if the word tomato was tomatoes in str, how can I still detect the tomato part and discard the es part?

Any suggestions or ideas ?

Answer 1

var list = new string[] { "Orange", "Lemon", "Pepper", "Tomato" };
var str = "Today, I ate a tomato and an orange.";

With LINQ and Regular Expressions you can check if string contains any keyword:

list.Any(keyword => Regex.IsMatch(str, Regex.Escape(keyword), RegexOptions.IgnoreCase));

Or get matched keywords:

var matched = list.Where(keyword =>
                Regex.IsMatch(str, Regex.Escape(keyword), RegexOptions.IgnoreCase));
// "Orange", "Tomato"

BTW this will match both tomatoes and footomato. If you need to match start of word, then search pattern should be changed a little: @"(^|\s)" + keyword