Java 8 coding preparation

-- if element is repeated , then ans will be wrong

so make use of distnce on stream 1st ,then sort it as below to get correct output

if there is onlt 1 element in array, then exception is thrown

Function.identity return same value which we pass as below

1st approach

===

2nd approach

==

ex:

3rd approach

--

below is the data

Optional

==

We can create optional object by below methos

1. empty()

this return optional.empty object

2.of(object)

if objct is null. then throw null pointerecxeption

3.ofNullable(obj)- if obj is null, then return optional.empty object

alays check ispresent as below

if obje is null, then it print default value as below

or you can throw exception