Hash code for Strings

HashCode

A brief introduction about  hashcode:-

1. Hash code integer representation of the memory  address  of the object
2. If two objects are equal  by equals method then their hashcode must be necessarily equal,vice-versa may need not be true.

Hash code generation for strings  is based on  below  formula,it overrides Hashcode method of Object Class

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

Where s[0] is the first character(ASCII value) in the string etc... 

           n is the length of the String

Note:- Hash code of empty string is zero,

1. Example 
1. String s4=new String("a");
2. System.out.println(s4.hashCode()+"  HashCode Value");

OutPut:- 97  HashCode Value