Difference between array, arraylist, List, Hashtable, Dictionary and SortedList in c#

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Basic difference is that arrays are of fixed size. Whereas an ArrayList implements the list data structure and can dynamically grow. While arrays would be more performance that a list, a list would be far more flexible since you don't need to know the required size initially. Array - represents an old-school memory array - kind of like a alias for a normal type[] array. Can enumerate. Can't grow automatically. I would assume very fast insertion, retrieve and speed. ArrayList - automatically growing array. Adds more overhead. Can enum., probably slower than a normal array but still pretty fast. These are used a lot in .NET List - one of my favorites - can be used with generics, so you can have a strongly typed array, e.g. List . Other than that, acts very much like ArrayList. Hashtable - plain old hashtable. O(1) to O(n) worst case. Can enumerate the value and keys properties, and do key/val pairs. Dictionary - same as above only strongly typed via generics, such a...
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What is Array in C sharp?

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  • An array is a collection of related instance either value or reference types. Array posses an immutable structure in which the number of dimensions and size of the array are fixed at instantiation.
  • C# Supports Single, Mult dimensional and Jagged Array.
  • Single Dimensional Array: it is sometimes called vector array consists of single row.
  • Multi-Dimensional Array: are rectangular & consists of rows and columns.
  • Jagged Array: also consists of rows & columns but in irregular shaped (like row 1 has 3 column and row 2 has 5 column)

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