Question

Calling Array.indexOf(input Array,"A") gives the index of “A” in input Array.But how to get all the index of “A” in the array if “A” occurs more than once in the input Array using a similar function.

Answer 1

int[] indexes = input.Select((item, index) => new { item, index })
                     .Where(x => x.item == "A")
                     .Select(x => x.index)
                     .ToArray();