Java String Program - Part 1

 Program 1

Write a program in Java to accept a string in lower case and change the first letter of every word to upper case. Display the new string.

Sample input: we are in cyber world

Sample output: We Are In Cyber World

import java.util.Scanner;

class P1{

    

    public static void change(){

        Scanner sc = new Scanner(System.in);

        System.out.println("Enter a sentence");

        

        String s = sc.nextLine();

        String newstr = "";

        

        s = s.toLowerCase();

        s = s.trim();

        s = " " + s;

        

        for(int i=0; i<s.length(); i++){

            char ch = s.charAt(i);

            if(ch == ' '){

                newstr = newstr + ch;

                newstr = newstr + Character.toUpperCase(s.charAt(i+1));

                i++;

            }

            else {

                newstr = newstr + ch;

            }

        }

        

        System.out.println("new string = " + newstr);

    }

}

Program 2

Write a program to accept a string. Convert the string into upper case letters. Count and output the number of double letter sequences that exist in the string

sample Input: SHE WAS FEEDING THE LITTLE RABBIT WITH AN APPLE

Sample Output:4

import java.util.Scanner;

class P2{

    

    public static void countDouble(){

        Scanner sc = new Scanner(System.in);

        System.out.println("Enter a sentence");

        String s = sc.nextLine();

        

        int count = 0;

        

        s = s.toUpperCase();

        

        for(int i =0; i<s.length()-1 ; i++){

            char ch = s.charAt(i);

            char ch1 = s.charAt(i+1);

            if(ch == ch1){

                count++;

            }

        }

        

        System.out.println("count of double letter seq = " + count);

    }}

        

Program 3

Special words are those words which start and end with the same letter.

Example: EXISTENCE, COMIC, WINDOW

Palindrome words are those words which read the same from left to right and vice-versa.

Example: MALYALAM, MADAM, LEVEL, ROTATOR, CIVIC

All palindromes are special words but all special words are not palindromes.

Write a program to accept a word. Check and display whether the word is a palindrome or only a special word or none of them.

import java.util.Scanner;

class P3{

    

    public static void check(){

        Scanner sc = new Scanner(System.in);

        System.out.println("Enter a word");

        String w = sc.next();

        

        boolean isSpecial = false;

        boolean isPalin = false;

        

        // decide if the word is a special word

        

        char fc = w.charAt(0);

        char lc = w.charAt(w.length()-1);

        

        if (fc == lc)

            isSpecial = true;

            

        String rev = "";

        for(int i = w.length()-1; i >= 0; i--){

            rev += w.charAt(i);

        }

        

        if(w.equals(rev))

            isPalin = true;

        

        if( isSpecial && isPalin )

            System.out.println(w + " is special and palindrome ");

        else if(isSpecial)

            System.out.println(w + " is special");

        else if(isPalin)

            System.out.println(w + " is palindrome ");

        else

            System.out.println(w + " is neither special nor palindrome ");

        }}   

Video explanations for these programs