Find String hashCode in Java

The Java hashCode method is one of the String Methods, which is to find and return the hashCode of the User specified string. The string hashCode value of an empty string is Zero, and this article will show how to use it with an example.

The formula behind the hashcode is: s[0]*31^(n-1) + s[1]*31^(n-2) + .. s(n-2). Here, s[i] is the i^th character of the user-specified string, and n is the string length. The syntax of the string hashCode in Java Programming language is

public int hashCode() // It will return the integer Value as Output

//In order to use in program
String_Object.hashCode()

• String_Object: Please specify the valid Object.

Example to find String hashCode in Java

In this program, we use this method to find the hashCode value of the user-specified string.

package StringFunctions;

public class HashcodeMethod {
	public static void main(String[] args) {
		String str = "Hi";
		
		int a = str.hashCode();
		int b = "Hello".hashCode();
		int c = "Java Programming".hashCode();
		int d = "hello world".hashCode();		
		int e = "tutorial gateway".hashCode();		

		System.out.println("Hashcode of the String str = " + a);
		System.out.println("Hashcode of the String = " + b);
		System.out.println("Hashcode of the String = " + c);
		System.out.println("Hashcode of the String = " + d);
		System.out.println("Hashcode of the String = " + e);
	}
}

The following statements will find the value of str.

int a = str.hashCode();

If you observe the above Java screenshot, the above statement returns 2337 as output. Let us find the same using the standard formula:

HashCode = s[0]*31^(n-1) + s[1]*31^(n-2) + .. s(n-2)

As we all know that the character at position 0 is H, the Character at position 1 is i, and the length is 2.

==> H*31^(2-1) + i*31^(2-2)

As we all know, the ASCII code of H is 72, and i is 105. It means,

==> 72 * 31 + 105 * 1 (Anything Power 0 is 1)

==> 2232 + 105 = 2337

TIP: Please refer ASCII Table to check the character codes of every character.

The following four statements will find the string hashCode of the sentence or text and then assign the values to the integer variables b, c, d, and e.

The last five System.out.println statements in this program will print the String Method output.