Search dictionary values and return List of keys meeting conditions

Question

I've got a problem searching a Dictionary looking like this.

Dictionary<string, string[]> dic = new Dictionary<string, string[]>(){
    {"a", new string[](){"a_val","2"}},
    {"b", new string[](){"b_val","1"}},
    {"b", new string[](){"b_val","0"}}
};

I need to return a List of the Keys where the value of the stingArray[1] element is bigger than "1" like:

List<string> list = new List<string>{
    "a"
};

Because I'm not really good at using LINQ, my current solution is iterating over the Dictionary and adding the keys to a new list. But that method looks ugly and I'm trying to find another solution to the problem.

Answer 1

Without any error handling:

var list = dic.Where(x => int.Parse(x.Value[1]) > 1)
              .Select(x => x.Key)
              .ToList();

With the Where statement the entries where Value[1] is greater 1 will be filtered and with the Select statement the key from this entries will be selected. At least the collection will be converted in a List with the ToList method.

For further information have a look at 101 LINQ Samples in C#

Answer 2

Try this(You're dictionary definition has some compiling errors and I made some guess):

        static void Main(string[] args)
    {
        var dic = new Dictionary<string, string[]>(){
        {"a", new string[]{"a_val","2"}},
        {"b", new string[]{ "b_val","1"}},
        {"c", new string[]{ "b_val","0"}}};
        string[] expected = dic
            .Where(kv => Convert.ToInt32(kv.Value[1]) > 1)
            .Select(kv => kv.Key).ToArray();
    }