Wednesday, 8 October 2014

Write a program to reverse a string

import java.util.*;
 class ReverseAString           //class name
{
   public static void main(String args[])  //main function
   {
      String original, reverse = "";    //string declaration
      Scanner in = new Scanner(System.in);                //to get input from- //-user

      System.out.println("Enter a string to reverse"); //Ask //string to reverse from user
original = in.nextLine();                            //getting input from user //using ‘in’ object

      int length = original.length();            //finding length of the //inputted string

      for ( int i = length - 1 ; i >= 0 ; i-- )  //using for loop //getting each character by using charAt(i) method
         reverse = reverse + original.charAt(i);  //reversed string is //stored in reverse string

      System.out.println("Reverse of entered string is: "+reverse);
//reversed sting is outputted to user
   }
}

Java Interview questions

·        Collections in java
·        Interfaces in java
·        Why static is used in public static void main()
Question
·        Difference between jre and jdk
Answer
·        JRE: Java Runtime Environment.
JRE basically the Java Virtual Machine where Java programs run on and  also includes browser plugins for Applet execution.
·        JDK: Java Development Kit

It is a Software Development Kit for Java, including JRE, and compilers and tools (eg. JavaDoc,, Java Debugger) to create and compile programs.