C# How to check string array elements is in string starting?

Question

I have a string arrary. Lets say as below

string[] lists = { "one", "two", "three"};

I have a string. Lets say as below

string title = "ONE_Page1";

I want to check, whether any of the array elements (lists) contains in my string starting (title).

Answer 1

So you want to check if any string in the list is a substring of your "main-string"?

bool contains = lists
    .Any(s => title.IndexOf(s, StringComparison.InvariantCultureIgnoreCase) >= 0);

If you don't want to compare case-insensitively you could use String.Contains which is more readable. But your sample data suggests that you want to compare case-insensitive.

Answer 2

There is always some hate for the Array.* functions, so here there is my variant :-)

string[] lists = { "one", "two", "three"};
string title = "ONE_Page1";

bool existsContain = Array.Exists(lists, x => title.IndexOf(x, StringComparison.InvariantCultureIgnoreCase) != -1);

bool existsStartsWith = Array.Exists(lists, x => title.StartsWith(x, StringComparison.InvariantCultureIgnoreCase));

It isn't clear if you want to match xxx_one_yyy (the fist one does it) or only "starts with" (so only one_yyy ) (the second one does it)

Note that instead of StringComparison.InvariantCultureIgnoreCase you could use StringComparison.CurrentCultureIgnoreCase , depending on how you want your app to behave with internationalization.

Answer 3

You can use some simple LINQ:

string[] lists = { "one", "two", "three"};
string title = "ONE_Page1";
bool titleStartsWithAnElementInLists = lists.Any(
    prefix => title.StartsWith(prefix, true, CultureInfo.InvariantCulture);