File Reading and Character Storage in Data Structures

Question

I have read a text file in C#. Now I want to store the characters in a data structure so that i can delete some of the read characters inside it. My concern is,

Which one (Data Structure: Array, List, List<>, Linked List etc) is fast?
How many characters each of the types can store?
Is it a good practice to load so many characters in memory like this?
Any other idea is appreciated please.

Vulpes · Answer

Taking those questions in the same order: 1. The fastest collection is the single dimensional array followed by List and then by LinkedList . An ArrayList is as fast as List for storing reference types but slower if you're storing value types (int double bool etc.) because of the need for 'boxing'. 2. All of these types can in theory store up to about 2 billion characters but in practice you'll probably have run out of memory well before then. 3. It depends what else you're doing and whether you in fact actually need to have them all in memory at once. 4. Difficult to make any suggestions without further information.