Java String Program Board Questions

1. Define a class to accept the gmail id and check for its validity. [15 MARKS - 2024]
   A gmail id is valid only if it has:
   
   

   @
   .(dot)
   gmail
   com
   
   Example: icse2024@gmail.com is a valid gmail id

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import java.util.*;

public class Prac
{
	public static void main(String args[])
	{
		Scanner sc=new Scanner(System.in);
		
		System.out.println("Enter gmail id : ");
		String s=sc.next();
		
		if(s.endsWith("@gmail.com"))
			System.out.println("Valid");
		else
			System.out.println("Not Valid");
			
	}
}

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2. Define a class to accept a String and print the number of digits, alphabets, spaces and special characters in the string. [15 MARKS - 2023]
   
   

   Example : 
   S = "KAPILDEV@83"
   
   Output : 
   Number of Digits - 2
   Number of Alphabets - 8
   Number of Spaces - 0
   Number of Special Characters - 1
   

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import java.util.*;

public class Prac
{
	public static void main(String args[])
	{
		Scanner sc=new Scanner(System.in);
		
		System.out.println("Enter a string :");
		String s=sc.nextLine();
		
		int digit=0, letter=0, space=0, special=0;
		
		for(int i=0; i<s.length(); i++) {
			char ch=s.charAt(i);
			
			if(Character.isDigit(ch))
				digit = digit + 1;
			
			else if(Character.isLetter(ch))
				letter = letter + 1;
			
			else if(Character.isWhitespace(ch))
				space = space + 1;
			
			else
				special = special + 1;
			
		}
		
		System.out.println("Number of Alphabets : " +letter);
		System.out.println("Number of Digits : " +digit);
		System.out.println("Number of Spaces : " +space);
		System.out.println("Number of Special Characters : " +special);
		
	}
}

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3. Define a class to accept a string, and print the characters with the uppercase and lowercase reversed, but all the other characters should remain the same as before. [15 MARKS - 2022]
   
   

   Example : 
   INPUT : 
   WelCoMe_2022
   
   OUTPUT : 
   wELcOmE_2022
   

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import java.util.*;

public class Prac
{
	public static void main(String args[])
	{
		Scanner sc=new Scanner(System.in);
		
		System.out.println("Enter a string :");
		String s1=sc.nextLine();
		
		String s2="";
		
		for(int i=0; i<s1.length(); i++) {
			char ch=s1.charAt(i);
			
			if(Character.isUpperCase(ch))
				ch=Character.toLowerCase(ch);
			
			else if(Character.isLowerCase(ch))
				ch=Character.toUpperCase(ch);
			
			s2=s2+ch;			
			
		}
		
		System.out.println("Original String is : "+s1);
		System.out.println("New String is : "+s2);
				
	}
}

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4. Write a program to input a sentence and convert it into uppercase and display each word in a separate line. [15 MARKS - 2020]
   
   

   Example : 
   INPUT : 
   India is my country
   
   OUTPUT : 
   INDIA
   IS
   MY
   COUNTRY
   

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import java.util.*;

public class Prac
{
	public static void main(String args[])
	{
		Scanner sc=new Scanner(System.in);
		
		System.out.println("Enter a string :");
		String s1=sc.nextLine();
		s1=s1+' ';
		
		String word="";
		
		for(int i=0; i<s1.length(); i++) {
			char ch=s1.charAt(i);
			
			if(ch==' ') {
				System.out.println(word);
				word="";
			}
			else {
				word=word+ch;
			}
			
		}
			
	}
}

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5. Write a program to input a sentence and convert it into uppercase and count and display the total number of words starting with a letter ‘A’. [15 MARKS - 2019]
   
   

   Example :
   INPUT : 
   ADVANCEMENT AND APPLICATION OF INFORMATION TECHNOLOGY ARE EVER CHANGING
   
   OUTPUT : 
   Total number of words starting with letter ‘A’ = 4
   

Click To See/Hide Answer

import java.util.*;

public class Prac
{
	public static void main(String args[])
	{
		Scanner sc=new Scanner(System.in);
		
		System.out.println("Enter a string :");
		String s1=sc.nextLine();
		
		s1=s1.toUpperCase()+' ';
		
		String word="";
		int count=0;
		
		for(int i=0; i<s1.length(); i++) {
			char ch=s1.charAt(i);
			
			if(ch==' ') {
				if(word.charAt(0)=='A') {
					count++;
				}
				word="";
			}
			else {
				word=word+ch;
			}
			
		}
		
		System.out.println("Total number of words starting with 'A' : "+count);
			
	}
}

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6. Write a program in Java to accept a string in lowercase and change the first letter of every word to uppercase. Display the new string. [15 MARKS - 2018]
   
   

   Example : 
   INPUT : 
   we are in cyber world
   
   OUTPUT : 
   We Are In Cyber World
   

Click To See/Hide Answer

import java.util.*;

public class Prac
{
	public static void main(String args[])
	{
		Scanner sc=new Scanner(System.in);
		
		System.out.println("Enter a string :");
		String s1=sc.nextLine();
		
		s1=' '+s1.toLowerCase();
		
		String s2="";
		
		for(int i=0; i<s1.length(); i++) {
			char ch=s1.charAt(i);
			
			if(ch==' ') {
				ch=s1.charAt(i+1);
				ch=Character.toUpperCase(ch);
				s2=s2+' ';
				i=i+1;
			}
			
			s2=s2+ch;
			
		}
		
		System.out.println("New string : "+s2.trim());
			
	}
}

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7. Write a program to accept a word, check and print whether the word is a palindrome or only special word. [15 MARKS - 2016]
   
   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 from left to right and vice-versa.
   

   Example : 
   MALAYALAM, MADAM, LEVEL, ROTATOR, CIVIC
   

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

Click To See/Hide Answer

import java.util.*;

public class Prac
{
	public static void main(String args[])
	{
		Scanner sc=new Scanner(System.in);
		
		System.out.println("Enter a string :");
		String s1=sc.next();
		s1=s1.toUpperCase();
		
		int len=s1.length();
				
		String rev="";
		
		for(int i=0; i<s1.length(); i++) {
			char ch=s1.charAt(i);
			
			rev=ch+rev;
			
		}
		
		if(s1.equals(rev))
			System.out.println("Palindrome String");
		
		else if(s1.charAt(0) == s1.charAt(len-1))
			System.out.println("Special Word");
		
		else
			System.out.println("Neither Palindrome Nor Special");
			
	}
}

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8. Write a program to assign a full path and file name as given below. Using library functions, extract and output the file path, file name and file extension separately as shown. [15 MARKS - 2014]
   
   

   Example : 
   INPUT : 
   C:\Users\admin\Pictures\flower.jpg
   
   OUTPUT : 
   Path : C:\Users\admin\Pictures\
   File name : flower
   Extension : jpg
   

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COMING SOON

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9. Write a program that encodes a word into Piglatin, To translate word into a Piglatin word, convert the word into uppercase and then place the first vowel of the original word as the start of the new word along with the remaining alphabets. The alphabets present before the vowel being shifted towards the end followed by “AY”. [15 MARKS - 2013]
   
   

   Example : 
   INPUT(1) : London
   OUTPUT(1)  : ONDONLAY
   
   INPUT(2) : Olympics
   OUTPUT(2) : OLYMPICSAY
   

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COMING SOON

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10. Write a program to accept a string. Convert the string to uppercase. Count and output the number of double letter sequences that exist in the string. [15 MARKS - 2012]
    
    

    Example : 
    INPUT : 
    SHE WAS FEEDING THE LITTLE RABBIT WITH AN APPLE
    
    OUTPUT  : 
    Number of double letter sequences = 4
    

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COMING SOON

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11. Write a program to accept a word and convert it into lower case, if it is in upper case. Display the new word by replacing only the vowels with the letter following it. [15 MARKS - 2011]
    
    

    Sample Input: 
    computer
    
    Sample Output: 
    cpmpvtfr
    

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COMING SOON

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12. Write a program to input a sentence. Count and display the frequency of each letter of the sentence in alphabetical order. [15 MARKS - 2010]
    
    

     Sample Input: APPLICATIONS Sample Output: Character - Frequency A - 2 P - 2 L - 1 C - 1 T - 1 I - 2 O - 1 N - 1 S - 1 

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COMING SOON

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