When will use to List and Hashtable

Question

Hi Can anyone explain when will use List and Hash table.Which scenario use this concepts??

Vulpes · Answer

You should use a List in situations where you need a dynamic array. An array is fixed in size once created but a List changes its size automatically as new elements are added. It also allows for elements to be inserted or removed from the List. Like an array it allows for elements to be retrieved by index (starting from 0). A Hashtable (or a generic Dictionary) is a collection of key/value pairs which allows a value to be retrieved very quickly from the collection using its key which must be unique (the values themselves don't need to be). Key/value pairs can be added to or removed from the Hashtable as required which like a List adjusts its size dynamically. Consequently you should use a Hashtable where fast access by key rather than by index is needed to the collection.