009 LEARNINGS

Data Abstraction is the property by virtue of which only the essential details are displayed to the user. abstraction is achieved by interfaces and abstract classes . Interfaces --- it does not have any defined methods so we can not make objects of interface. Classes implements interfaces   example -- public interface car { public boolean ispetrolcar(); public boolean enginetype(); } class automobile implements car{ ispetrolcar(){ return true} enginetype(){ return petrol;} }

where child class inherits parent class features with its own features . that we don't have to write code again and again Parent class ----  class   human being  Child class ---  class male extends human being

  Object Oriented Programming is used to implement real world  entities like inheritance, hiding, polymorphism etc in programming. Class :- it is a  definition  ---- mamals >human beings > male                                                                                        >female Object :- male guri=new male();

A left rotation operation on an array shifts each of the array's elements 1 unit to the left. For example, if 2 left rotations are performed on array [1,2,3,4,5] , then the array would become [3,4,5,1,2] . Given an array a of n integers and a number, d , perform d left rotations on the array. Return the updated array to be printed as a single line of space-separated integers. CODE :- import java.io.*; import java.math.*; import java.security.*; import java.text.*; import java.util.*; import java.util.concurrent.*; import java.util.regex.*; public class Solution {     // Complete the rotLeft function below.     static int[] rotLeft(int[] a, int d)      {              int[] b= new int[a.length];         for(int i =0;i<d;i++){             b[a.length-d+i]=a[i];         }         for(int i =d;i<a.length;i++){     ...