C# String - GetHashCode() Method

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The C# String GetHashCode() method is used to determine a has code for a string. A hash code is a numerical value that represents the content of an object, such as a string and is often used in hashing algorithms and data structures like hash tables.

Syntax

Following is the syntax of the C# string GetHashCode() method −

 public override int GetHashCode (); 

Parameters

This method does not accepts any parameters.

Return value

This method returns a 32-bit signed integer has code.

Example 1: Display hashCode of the string.

Following is the basic example of theGetHashCode()method to get hash code of all the specified string −

 using System; class Program { static void Main() { string str1 = "Hello"; string str2 = "tutotisldpoint"; string str3 = "India"; Console.WriteLine($"Hash code for '{str1}': {str1.GetHashCode()}"); Console.WriteLine($"Hash code for '{str2}': {str2.GetHashCode()}"); Console.WriteLine($"Hash code for '{str3}': {str3.GetHashCode()}"); } } 

Output

Following is the output −

 Hash code for 'Hello': -498165893 Hash code for 'tutotisldpoint': 1462438067 Hash code for 'India': -1602197555 

Example 2: Using GetHashCode in a Dictionary

Let us look at another example of the GetHashCode() method to get the hash code of the dictionary's elements −

 using System; using System.Collections.Generic; class Program { static void Main() { Dictionary<int, string> hashDict = new Dictionary<int, string>(); string[] fruits = { "apple", "guava", "cherry", "banana" }; foreach (string word in fruits) { int hash = word.GetHashCode(); hashDict[hash] = word; Console.WriteLine($"Word: {word}, Hash Code: {hash}"); } int hashToFind = "banana".GetHashCode(); Console.WriteLine($"Value for hash code {hashToFind}: {hashDict[hashToFind]}"); } } 

Output

Following is the output −

 The number of vowels in the string is: 5 

Example 3: Comparing Hash Code of a String

In this example, we use the GetHashCode() method to get the hashcode of the specified string and compare the hash codes of each string −

 using System; class Program { static void Main() { string str1 = "tutorialspoint"; string str2 = "India"; string str3 = "tutorialspoint"; // Get hash codes for the strings int hash1 = str1.GetHashCode(); int hash2 = str2.GetHashCode(); int hash3 = str3.GetHashCode(); Console.WriteLine($"Hash code for '{str1}': {hash1}"); Console.WriteLine($"Hash code for '{str2}': {hash2}"); Console.WriteLine($"Hash code for '{str3}': {hash3}"); // Check if hash codes match Console.WriteLine($"Hash code of '{str1}' and '{str2}' are equal: {hash1 == hash2}"); Console.WriteLine($"Hash code of '{str1}' and '{str3}' are equal: {hash1 == hash3}"); } } 

Output

Following is the output −

 Hash code for 'tutorialspoint': -246238028 Hash code for 'India': -1602197555 Hash code for 'tutorialspoint': -246238028 Hash code of 'tutorialspoint' and 'India' are equal: False Hash code of 'tutorialspoint' and 'tutorialspoint' are equal: True