akhansari

Guidelines and rules for GetHashCode

What is GetHashCode used for?

It is by design useful for only one thing: putting an object in a hash table. Hence the name.

Why do we have this method on Object in the first place?

It makes perfect sense that every object in the type system should provide a GetType method; data's ability to describe itself is a key feature of the CLR type system. And it makes sense that every object should have a ToString, so that it is able to print out a representation of itself as a string, for debugging purposes. It seems plausible that objects should be able to compare themselves to other objects for equality. But why should it be the case that every object should be able to hash itself for insertion into a hash table? Seems like an odd thing to require every object to be able to do.

akhansari

// class
var Greeter = (function () {

	// constructor
	function Greeter(message) {

		// public variable
		this.greeting = message;

akhansari

[Code]

function LoadValueFromXML(const AFileName, APath: string): string;
var
	XMLNode: Variant;
	XMLDocument: Variant;  
begin
	Log('Get Xml text node: ' + AFileName);
	Result := '';

akhansari

public string Hash(string str)
{
	return string.Join("", System.Security.Cryptography.SHA256.Create()
		.ComputeHash(System.Text.Encoding.UTF8.GetBytes(str)).Select(s => s.ToString("x2")));
}

akhansari

1078	af
1052	sq
14337	ar-ae
15361	ar-bh
5121	ar-dz
3073	ar-eg
2049	ar-iq
11265	ar-jo
13313	ar-kw