Question

Design a class Exchange to accept a sentence and interchange the first alphabet with the last
alphabet for each word in the sentence,with single letter word remaining unchanged. The words in the input sentence are separated by a single blank space and terminated by a full stop.
Example: Input: It is a warm day.
Output: tI si a marw yad
Some of the data members and member functions are given below:

Classname:Exchange
Data members / instance variables:

sent:stores the sentence
rev:to store the new sentence
size: stores the length of the sentence

Member functions:

Exchange(): default constructor
void readsentence():to accept the sentence

void exfirstlast():extract each word and interchange the first and last alphabet of the word and form a new sentence rev using the changed words

void display():display the original sentence along with the new changed sentence.

Specify the class Exchange giving details of the constructor(), void readsentence() , void exfirstlast() and void display(). Define the main() function to create an object and call the functions accordingly to enable the task.

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Code

				
					import java.util.Scanner;
public class Exchange
{
    String sent,rev;
    int size;
    Exchange()
    {
        sent="";
        rev="";
        size=0;
    }

    void readsentence()
    {
        Scanner sc=new Scanner(System.in);
        System.out.print("Enter a sentence");
        sent=sc.nextLine();
        size=sent.length();
    }
    
    void exfirstlast()
    {
        char ch=' ';
        String wd="";
        for(int i=0;i< size;i++)
        {    
            ch=sent.charAt(i);
            if(ch==' '||ch=='.')
            { 
                if(wd.length()>1)
                {
                    /*last character*/
                    rev=rev + wd.charAt(wd.length()-1);
                    /*middle characters*/
                    rev=rev + wd.substring(1,wd.length()-1);
                    /*first character*/
                    rev=rev + wd.charAt(0);
                    /*space or full stop*/
                    rev=rev+ch;
                }
                else
                {
                    rev=rev+wd+ch;
                }

                wd="";
            }
            else
            {
                wd=wd+ch;
            }
        }
    }

    void display()
    {
        System.out.println("Input:"+sent);
        System.out.println("Output: "+rev);
    }

    public static void main()
    {
        Exchange obj1=new Exchange();
        obj1.readsentence();
        obj1.exfirstlast();
        obj1.display();
    }
}