Скачать или смотреть 28. What is Hashcode method / Hashing technique in java with practical

What is Hashcode method Hashing technique
Method convert the input int/string/object into the int value by using some arithmetic's

HashCode method For Integer
public static int hashCode(int value) {
return value;
}

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

HashCode method For character
public static int hashCode(char value) {
return (int)value;
}

Demo program :
package com.techiedeveloper.set;

public class HashSetDemo {

public static void main(String[] args) {
Integer i = 10;
System.out.println(i.hashCode());

Character c = 'a';
System.out.println(c.hashCode());

String s = new String("abc");
System.out.println(s.hashCode());

String s1 = new String("abc");
System.out.println(s == s1);
System.out.println(s.equals(s1));

}

}