Question

To convert a list to a dictionary, we can do it easily with the follwing:

list.ToDictionary(v=> v, v=>true);

For the first parameter in ToDictionary, I can understand the first parameter is the element of the dictionary. But what is meant by v=> true?

The second parameter should be of the type IEqualityComparer. What purpose does this serve? How is v=> true same as IEqualityComparer?

Answer 1

This is the method is used.

The second parameter (v => true) is the elementSelector (A transform function to produce a result element value from each element).

A list with the elements 1, 2 and 3 would result in a dictionary with the following mapping (all values are true):

1: true
2: true
3: true