How to loop through a list and filter items starting with 'OO' in C#?

I need to loop the List and then extract the specified items which starts with ‘OO’ to New list

Here is my code :-

List<string> mylist = new List<string>() 
Mylist.add(“5876575”);
Mylist.add(“OO12571”);
Mylist.add(“12287324”);
Mylist.add(“87665751”);
Mylist.add(“97213233”);
Mylist.add(“87612222”);
Mylist.add(“OO76566”);


List<string> matches = new List<string>() 
matches = myList.Where(x => x[0] == 'OO').ToList();

My above code is not working – Please help me.
Output should be Matches list should only contains any item in the list which starts with ‘OO’ :-
Matches = OO12571, OO76566

>Solution :

Well, your attached code has plenty of compilation errors.

Assume that you have fixed it, there are quite some alternatives to filter the string in the array/list with starts with "OO".

1. string.StartsWith() as suggested by @Charlieface

matches = mylist.Where(x => x.StartsWith("OO"))
    .ToList();

2. Take the first 2 characters with string.Substring(0, 2).

matches = mylist.Where(x => x.Substring(0, 2) == "OO")
    .ToList();

3. Working with Regex.

using System.Text.RegularExpressions;

Regex regex = new Regex("^OO");
matches = mylist.Where(x => regex.IsMatch(x))
    .ToList();