Write a program to swap the first letter of a word with the first letter of the next word, for each of the word in a given string. Assume that the string starts and ends with a letter, has no punctuation marks and has exactly one space between two words. Also assume that there are even number of words in the string.

s = 'hello world';

Wanted = swap(s) % function call

% function

function Wanted = swap(str)

S = regexp(str,'\S*','match');

S([1,end]) = S([end,1]);

Wanted = strjoin(S);

end

or better still

% Create sample string.

str = 'one two three four five';

% Split apart into individual words without spaces.

words = strsplit(str)

% Swap the first and last words.

[words(end), words(1)] = deal(words(1), words(end))

% String the words together with spaces between them.

outputString = ''; % Initialize output

for k = 1 : length(words)

outputString = sprintf('%s ', outputString, words{k});

end

% Trim off the leading and trailing spaces.

outputString = strtrim(outputString)

Explanation:

all codes are written in matlab programming language.

// Scanner class is imported to allow program

// receive user input

import java.util.Scanner;

// class Solution is defined

public class Solution {

// main method that begin program execution

public static void main(String args[]) {

// Scanner object scan is defined

// to receive input via the keyboard

Scanner scan = new Scanner(System.in);

// prompt is display to user to enter two word

System.out.println("Enter your two-word: ");

// user input is assigned to user_input

String user_input = scan.next();

// user_input is splitted using space as separator

String[] splitted_input = user_input.split(" ");

// first word from the array is assigned to first_word

String first_word = splitted_input[0];

// second word from the array is assigned to second_word

String second_word = splitted_input[1];

// first character of first_word is assigned to temp

char temp = first_word.charAt(0);

// new_first_word is form by concatenating first character of second_word

// and substring of first_word

String new_first_word = second_word.charAt(0) + first_word.substring(1);

//new_second_word is form by concatenating the temp and

// substring of second_word

String new_second_word = temp + second_word.substring(1);

// the new words are displayed to the user

System.out.println("The new word is: \n" + new_first_word + " " + new_second_word);

}

}

Explanation:

The code is written in Java and well commented.