Briefly explain the difference between ArrayList and Dictionary in C#?
=> asked by Jae Lee
ArrayList is to create an array by storing object references. This means it can store anything and it would have "boxing" overhead when storing to ArrayList.
ArrayList belongs to the days that C# did not have generics. It is not used that much these days in favor of List
Dictionary represents a sophisticated data structure that allows you to access an element based on a key. Dictionary is also known as hash tables or maps. The main feature of dictionary is fast lookup based on keys. You can also add and remove items freely, a bit like a List