C# Dictionary Hash Table and sets
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This document discusses dictionaries, hash tables, and hash sets in C#. It describes dictionaries as a generic collection of key-value pairs where each key is unique. It lists common dictionary methods like adding, removing, finding, and replacing elements. Hash tables are described as storing key-value pairs where keys are used to locate values. Common hash table properties and methods are listed. Finally, it defines hash sets as ensuring there are no duplicate elements like strings in a collection.
![Remove element:
Dict.Remove(“Compact");
Add element:
Dict.Add(“Compact", 21);
Methods in C# Dictionaries
In C#, A dictionary can provide methods like:
Find element:
if (!Dict.ContainsKey(“Compact")) {
Dict[“Compact"] = 20;
}
Replace element:
Dict[“Compact"] = 8;](https://image.slidesharecdn.com/c-dictionary-hashtable-and-sets-220616200943-c4eded36/85/C-Dictionary-Hash-Table-and-sets-7-320.jpg)
C# Dictionary Hash Table and sets
- 2. Agenda
- 3. What is C# Dictionaries? Methods in C# Dictionaries What is C# Hash-table? Properties of C# Hash-table Methods in C# Hash-table C# Hash-set Implementation
- 4. What are C# Dictionaries?
- 5. What are C# Dictionaries? A generic namespace is a class that can include any type of data in the form of keys and values. Dictionary is a class defined in the System.Collections package. The Dictionary class in C# is a generic collection of key- value pairs. Each key in the collection must be unique. Syntax: Dictionary<string, string> Dict = new Dictionary<string, string>();
- 7. Remove element: Dict.Remove(“Compact"); Add element: Dict.Add(“Compact", 21); Methods in C# Dictionaries In C#, A dictionary can provide methods like: Find element: if (!Dict.ContainsKey(“Compact")) { Dict[“Compact"] = 20; } Replace element: Dict[“Compact"] = 8;
- 8. What are C# Hash-tables?
- 9. What are Hash-tables? KEY VALUE 1 11 2 22 3 33 4 44 Each DictionaryEntry object in the collection has two properties: a key and a value. A Hash-Table can't have duplicate entries because it's immutable. In C#, a Hash-table stores (Keys, Values) pairs, where Keys can locate the storage. The table's values can only be accessed by defining key object. Syntax: Hashtable HT = new Hashtable();
- 10. Properties of C# Hash-table
- 11. Properties of C# Hash-table Comparer: Returns or sets the IComparer to be used. KEY VALUE 1 11 2 22 3 33 4 44 Count: Gets the number of key/value pairs contained in the hash table. IsReadOnly: Returns a value indicating if the hash table is a read-only hash table. Item: Returns or sets the value corresponding to the provided Key. Keys: Returns an ICollection holding the hash table's keys. Values: Returns an ICollection holding the hash table's values.
- 12. Methods in C# Hash-table
- 13. Methods in C# Hash-table Various methods in a hash table are: Add: Inserts an element in the hash table with the provided key and value. KEY VALUE 1 11 2 22 3 33 4 44 Clear: Clears the hash table of all its elements. ContainsKey: Indicates whether or not the hash table contains the supplied key. ContainsValue: Indicates whether or not the hash table contains the specified value.
- 14. C# Hash-sets
- 15. C# Hash-sets Sets in C# are called HashSet. HashSet in C# makes sure there aren't any duplicate strings or elements in an array. Value ‘John’ ‘Mary’ ‘Eddie’ ‘Tony’ ‘Snow’ ‘Ray’ Syntax: var h = new HashSet<string>(arr1);
- 16. Implementation