Index and distinct operators

- With the Lambda syntax in place,…I want to add some functionality that I was not…able to access with comprehension syntax,…to specify an index when filtering.…Let's consider this large sequence…consisting of amount of money customers have spent…in three different currencies.…These are results from a cross product query…where the price properties for each customer…was multiplied with an exchange rate…to give the value in three different currencies:…euro, pound and yen.…I know that every third item in the list…corresponds to the same currency.…

I can use an indexed where query to pull one set…of currency values from the list.…In this case, I'm going to pull out all the values in yen.…I'll scroll back to my main program.…I'll start a new query with the name of my query…in a source sequence.…I'll introduce the range variable and the index variable…to the left of the Lambda symbol.…I know the third element and every third element after that…is also in yen, so I'll set the Lambda expression…to grab every third element in the sequence.…