Combine Multiple Predicates

Question

Is there any way in c# .NET 2.0! to combine multiple Predicates?

Let\'s say I have the following code.

List names = new List

        

Answer 1

You could wrap the predicate method into a class and have the constructor accept an array of strings to test for:

class StartsWithPredicate
{
    private string[] _startStrings;
    public StartsWithPredicate(params string[] startStrings)
    {
        _startStrings = startStrings;
    }
    public bool StartsWith(string s)
    {
        foreach (var test in _startStrings)
        {
            if (s.StartsWith(test))
            {
                return true;
            }
        }
        return false;
    }
}

Then you can make a call like this:

List filtered = names.FindAll((new StartsWithPredicate("E", "I")).StartsWith);

That way you can test for any combination of input strings without needing to extend the code base with new variations of the StartsWith method.