IndexOf with Linq, accepting lambda expression

Question

Is there a way to find the index from list of partial prefixes with Linq, something like:

List<string> PartialValues = getContentsOfPartialList();
string wholeValue  = "-moz-linear-gradient(top,  #1e5799 0%, #7db9e8 100%)";
int indexOfPartial = PartialValues
                      .IndexOf(partialPrefix=>wholeValue.StartsWith(partialPrefix));

Unfortunately, IndexOf() doesn't accept lambda expression. Is there a similar Linq method for this?

Answer 1

You don't need LINQ at all, List<T> has a method FindIndex.

int indexOfPartial = PartialValues
    .FindIndex(partialPrefix => wholeValue.StartsWith(partialPrefix));

For the sake of completeness, you can use LINQ, but it's not necessary:

int indexOfPartial = PartialValues
  .Select((partialPrefix , index) => (partialPrefix , index))
  .Where(x => wholeValue.StartsWith(x.partialPrefix))
  .Select(x => x.index)
  .FirstOrDefault(-1);