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.

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

Video Link:

YouTube Video

Solution:

import java.util.Scanner;

public class Year2018Q1

{

    public static void main(String args[])

    {

        Scanner sc = new Scanner(System.in);

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

        String str = sc.nextLine();

        str=" "+str;

        String word = "";

        for (int i = 1; i < str.length(); i++)

        {

            if (str.charAt(i - 1) == ' ')

            {

                word = word + Character.toUpperCase(str.charAt(i));

            }

            else

            {

                word = word + str.charAt(i);

            }

        }

        System.out.println(word);

    }

}

Output:

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'.

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'.

Example:

Sample Input: ADVANCEMENT AND APPLICATION OF INFORMATION TECHNOLOGY ARE EVER CHANGING.

Sample Output : Total words starting with letter 'A' = 4.

Solution:

import java.util.Scanner;

public class Year2019Q1

{

    public static void main(String args[])

    {

        Scanner in = new Scanner(System.in);

        System.out.println("Enter a string: ");

        String str = in.nextLine();

        str = " " + str;

        int count = 0;

        int len = str.length();

        str = str.toUpperCase();

        for (int i = 0; i < len - 1; i++)

        {

            if (str.charAt(i) == ' ' && str.charAt(i + 1) == 'A')

            {

                count++;

            }

        }

        System.out.println("Total words starting with letter 'A' = " + count);

    }

}

Output:

Define a class to accept two strings of same length and form a new word in such a way that, the first character of the first word is followed by the first character of the second word and so on.

Define a class to accept two strings of same length and form a new word in such a way that, the first character of the first word is followed by the first character of the second word and so on.

Example:

Input string 1-BALL

Input String 2- WORD

OUTPUT: BWAOLRLD

Solution:

import java.util.Scanner;

public class Year2022Q3

{

    public static void main(String[] args)

    {

        Scanner sc = new Scanner(System.in);

        String st1,st2;

        String newStr = "";

        System.out.println("Enter 2 string of same length: ");

        System.out.print("Enter first string:");

        st1 = sc.nextLine();

        System.out.print("Enter second string:");

        st2 = sc.nextLine();

        int len = st1.length();

        for (int i = 0; i < len; i++)

        {

            newStr = newStr + st1.charAt(i) + st2.charAt(i);

        }

        System.out.println(newStr);

    }

}

Output:

Define a class to declare an array to accept and store ten words. Display only those words which begin with the letter 'A' or 'a' and also end with the letter 'A' or 'a'.

Define a class to declare an array to accept and store ten words. Display only those words which begin with the letter 'A' or 'a' and also end with the letter 'A' or 'a'.

EXAMPLE:

Input: Hari, Anita, Akash, Amrita, Alina, Devi, Rishab, Jolin, Farha, AMITHA

Output:

Anita

Amrita

Alina

AMITHA

Solution:

import java.util.Scanner;

public class Year2022Q2

{

    public static void main(String[] args)

    {

        String names[] = new String[10];

        Scanner sc = new Scanner(System.in);

        int len = names.length;

        System.out.println("Enter 10 name:");

        for (int i = 0; i < len; i++)

        {

             names[i]=sc.nextLine();

        }

        System.out.println("Names are:");

        for (int i = 0; i < len; i++)

        {

            int lastIndex = names[i].length() - 1;

            if((names[i].charAt(0)=='a'

                ||names[i].charAt(0)=='A')

                &&(names[i].charAt(lastIndex)=='a'

                ||names[i].charAt(lastIndex)=='A'))

            {

                System.out.println(names[i]);

            }

        }

    }

}

Output:

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

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.

EXAMPLE:

INPUT: WelCoMe_2022

OUTPUT: wELcOmE_2022

Video Link:

YouTube Video

Solution:

import java.util.Scanner;

public class Year2022Q1

{

    public static void main(String[] args)

    {

       

        Scanner sc = new Scanner(System.in);

        System.out.println("Enter a string: ");

        String str = sc.nextLine();

        String newStr="";

        int len=str.length();

//      Method 1

        for(int i=0;i<len;i++)

        {

            char ch=str.charAt(i);

            if(Character.isUpperCase(ch))

                newStr = newStr + Character.toLowerCase(ch);

            else if(Character.isLowerCase(ch))

                newStr += Character.toUpperCase(ch);

            else

                newStr+=ch;

        }

       

//      Method 2

        for(int i=0;i<len;i++)

        {

            char ch=str.charAt(i);

            if(ch>='A' && ch<='Z')

                newStr = newStr + Character.toLowerCase(ch);

            else if(ch>='a' && ch<='z')

                newStr += Character.toUpperCase(ch);

            else

                newStr+=ch;

        }

        System.out.println(newStr);

    }

}

Output:

Define a class to accept a string and print number of digits, alphabets and special characters in the string.

Define a class to accept a string and print number of digits, alphabets and special characters in the string.

Example: 

Input:     S = KAPILDEV@83

Output:  Number of Digits - 2

              Number of Alphabets - 8

              Number of Special Characters - 1

                 

Solution:

import java.util.Scanner;

public class Year2023Q1

{

    public static void main(String[] args)

    {

        Scanner sc = new Scanner(System.in);

        System.out.println("Enter a string:");

        String str = sc.nextLine();

        int len=str.length();

        int digitCount=0,letterCount=0,whitespaceCount=0,spclCharCount=0;

       

//      Method 1

        for(int i=0;i<len;i++)

        {

            char ch=str.charAt(i);

            if(ch>='0' && ch<='9')

                digitCount++;

            if(ch>='A' && ch<='Z'|| ch>='a' && ch<='z')

                letterCount++;

            if(ch==' ')

                whitespaceCount++;

            spclCharCount=len-(digitCount+letterCount+whitespaceCount);

        }

       

//      Method 2    

        for(int i=0;i<len;i++)

        {

            char ch=str.charAt(i);

            if(Character.isDigit(ch))

                digitCount=digitCount+1;

            if(Character.isLetter(ch))

                letterCount+=1;

            if(Character.isWhitespace(ch))

                whitespaceCount++;

            spclCharCount=len-(digitCount+letterCount+whitespaceCount);

        }

       

        System.out.println("Number of digits = "+digitCount);

        System.out.println("Number of letters = "+letterCount);

        System.out.println("Number of special Char = "+spclCharCount);

        System.out.println("Number of whitespace = "+whitespaceCount);  

    }

}

Output:

Methods in Java

What is method?

What is the advantages of using methods?

What is method prototype?

What is method signature?

What is formal parameter?

What is actual parameter?

Code 01

1. import java.util.Scanner;
2. public class ParkingLot 
3. {
4. int vno;
5. int hours;
6. double bill;
7. public static void main(String args[])
8. {
9. ParkingLot ob = new ParkingLot();
10. ob.input();
11. ob.calculate();
12. ob.display();
13. }
14. void input()
15. {
16. Scanner sc = new Scanner(System.in);
17. System.out.print("Enter the vehicle number: ");
18. vno = sc.nextInt();
19. System.out.print("Enter the hours vehicle is parked: ");
20. hours = sc.nextInt();
21. }
22. void calculate()
23. {
24. if(hours<=1)
25. bill = 3;
26. else
27. bill = 3+(hours-1)*1.5;
28. }
29. void display()
30. {
31. System.out.println("Vehicle Number = "+vno);
32. System.out.println("Hours Parked = "+hours);
33. System.out.println("Bill Amount = "+bill);
34. }
35. }

-------------------------------------------------------------------------------------------

Code 02:

1. import java.util.Scanner;
2. public class FunctionOverload 
3. {
4. void compare(int a,int b)
5. {
6. if(a>b)
7. System.out.println(a+" is greater.");
8. else if(a<b)
9. System.out.println(b+" is greater.");
10. else
11. System.out.println("Both are equal.");
12. }
13. void compare(char a,char b)
14. {
15. if((int)a>(int)b)
16. System.out.println(a+" is greater.");
17. else if((int)a<(int)b)
18. System.out.println(b+" is greater.");
19. else
20. System.out.println("Both are equal.");
21. }
22. void compare(String a,String b)
23. {
24. int l1 = a.length();//6
25. int l2 = b.length();//7
26. if(l1>l2)
27. System.out.println(a+" is greater in length");
28. else if(l1<l2)
29. System.out.println(b+" is greater in length");
30. else
31. System.out.println("Both are equal");
32. }
33. public static void main(String args[])
34. {
35. FunctionOverload ob = new FunctionOverload();
36. Scanner sc = new Scanner(System.in);
38. int p,q;
39. p = sc.nextInt();
40. q = sc.nextInt();
41. ob.compare(p,q);
43. char ch1,ch2;
44. ch1 = sc.next().charAt(0);
45. ch2 = sc.next().charAt(0);
46. ob.compare(ch1,ch2);
48. String s1,s2;
49. s1 = sc.next();
50. s2 = sc.next();
51. ob.compare(s1,s2);
52. }
53. }

Previous Year Questions on Strings

ICSE Class 10 Computer Applications 
Previous Year Questions on String

Year 2023

Question 1

Define a class to accept a string and print number of digits, alphabets and special characters in the string.

Example:      

INPUT:        S = KAPILDEV@83

OUTPUT:    Number of Digits - 2

                    Number of Alphabets - 8

                    Number of Special Characters - 1

Solution

Year 2022

Question 2

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

EXAMPLE:

INPUT: WelCoMe_2022

OUTPUT: wELcOmE_2022

Solution

YouTube Video Link

Question 3

Define a class to declare an array to accept and store ten words. Display only those words which begin with the letter 'A' or 'a' and also end with the letter 'A' or 'a'

EXAMPLE:

Input: Hari, Anita. Akash, Amrita, Alina, Devi, Rishab, Jolin, Farha, AMITHA

Output:

Anita

Amrita

Alina

AMITHA

Solution

Question 4

Define a class to accept two strings of same length and form a new word in such a way that, the first character of the first word is followed by the first character of the second word and so on.

Example:

Input string 1-BALL

Input String 2- WORD

OUTPUT: BWAOLRLD

Solution

Year 2019

Question 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'.

Example:

Sample Input: ADVANCEMENT AND APPLICATION OF INFORMATION TECHNOLOGY ARE EVER CHANGING.

Sample Output : Total number of words starting with letter 'A' = 4.

Solution

Year 2018

Question 6

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

Solution

YouTube Video Link

Year 2017

Question 7

Design a class to overload a function check ( ) as follows : 

(i) void check (String str, char ch) – to find and print the frequency of a character in a string.

Example : *

Input:

str = “success”

ch = ‘s’ .

Output:

number of s present is = 3

(ii) void check(String si) – to display only vowels from string si, after converting it to lower case.

Example:

Input:

s1 = “computer”

Output:

o u e

Year 2016

Question 8

Special words are those words which starts and ends with the same letter. 

Examples:

EXISTENCE

COMIC

WINDOW

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

Examples:

MALAYALAM

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 print Whether the word is a palindrome or only special word.

Solution

Year 2015

Question 9

Design a class to overload a function Joystring( ) as follows :

(i) void Joystring (String s, char ch1 char ch2) with one string argument and two character arguments that replaces the character argument ch1 with the character argument ch2 in the given string s and prints the new string.

Example:

Input value of s = “TECHNALAGY”

ch1=‘A’,

ch2=‘O’

Output: TECHNOLOGY

(ii) void Joystring (String s) with one string argument that prints the position of the first space and the last space of the given string s.

Example:

Input value of = “Cloud computing means Internet based computing”

Output: First index : 5

Last index : 36

(iii) void Joystring (String s1, String s2) with two string arguments that combines the two string with a space between them and prints the resultant string. 

Example :

Input value of s1 =“COMMON WEALTH”

Input value of s2 =“GAMES”

Output: COMMON WEALTH GAMES

(use library functions) 

Solution

Different type of numbers generally asked in Java ICSE Board exams

1. Disarium Number

2. Amicable Pair

3. Unique Number

4. BUZZ number

My only motive is to provide you most simplest and easy way to do coding. Targeted Audience ICSE 9th and 10th Class. More numbers will be added soon.........................

Question 1 : Disarium Number

Write a java program to check whether the entered number is a Disarium Number. A number is called a Disarium if sum of the digits powered with its respective positions is equal to original number itself.

For example: 175 is a Disarium number.
175 = 1¹+7²+5³ = 1+49+125 = 175
Here in this program we will be using Scanner class to take the input from the user.

import java.util.Scanner;
public class Disarium 
{
public static void main(String args[])
{
Scanner sc = new Scanner(System.in);
System.out.print("Enter a number : ");
int num = sc.nextInt();
int temp = num, rem = 0, sum = 0;//to keep original number intact taking temp 
String s = Integer.toString(num);  
int len = s.length();  //to calculate the length of number converted to string
while(temp>0)
{
rem = temp % 10;  
sum = sum + (int)Math.pow(rem,len--);
temp =  temp/10;
}
if(sum == num) //to check whether the original number is equal to the sum
System.out.println("Disarium Number.");
else
System.out.println("Not a Disarium Number.");
}

}

Output of the code:

----------------------------------------------------------------------------------------------------------

Question 2 : Amicable Pair

Write a java program to check whether the entered pair is a Amicable Pair. Amicable pair are so related that sum of proper divisors of each is equal to other number.

Amicable numbers are:(220,284), (1184,1210), (2620,2924), (5020,5564), etc.
For Example: 220 and 284 are amicable pair.
Divisors of 220 = 1,2,4,5,10,11,20,22,44,55,110
Sum of divisors of 220 = 1+2+4+5+10+11+20+22+44+55+110  = 284
Divisors of 284 = 1,2,4,71,142
Sum of divisors of 284 = 1+2+4+71+142 = 220
Here 284 is not equal to 220. And sum of divisors is equal to other number itself.

import java.util.Scanner;
public class AmicableNumber 
{
public static void main(String args[]) 
{
Scanner sc = new Scanner(System.in);
System.out.print("Enter first number: ");
int num1 = sc.nextInt();
System.out.print("Enter second number: ");
int num2 = sc.nextInt();
int sumNum1 = 0, sumNum2 = 0;
for(int i=1;i<num1;i++) 
{
if (num1%i==0)
sumNum1 = sumNum1+i;
}
for(int i=1;i<num2;i++) 
{
if (num2%i==0)
sumNum2 =sumNum2+i;
}
if ((sumNum1 == num2) && (sumNum2 == num1) && (num1!=num2))
System.out.println("Amicable pair");
else
System.out.println("Not amicable pair");
}
}

Output of the code:

----------------------------------------------------------------------------------------------------------

Question 3 : Unique Number

Write a java program to check whether the entered number is a Unique Number or not. A number that does not have any duplicate digit is called Unique Number.

For example: 12345, 3456 are unique numbers.

122323, 2323 are not unique numbers.

import java.util.Scanner;

public class UniqueNumber 

{

public static void main(String args[])

{

Scanner sc = new Scanner(System.in);

System.out.println("Enter a number: ");

int num = sc.nextInt();

boolean flag = false;

String str = Integer.toString(num);

int len = str.length();

for(int i=0;i<len-1;i++)

{

for(int j=i+1;j<len;j++)

{

if(str.charAt(i)==str.charAt(j))

{

flag = true;

break;

}

}

}

if(flag==false)

System.out.println("Unique Number");

else

System.out.println("Not Unique");

}

}

Output of the code:

----------------------------------------------------------------------------------------------------------

Question 4 : BUZZ Number

Write a java program to check whether the entered number is a BUZZ number or not. BUZZ number are those numbers whose last digit is 7 or divisible by 7.

import java.util.Scanner;

public class Buzz 

{

public static void main(String[] args) 

{

Scanner sc = new Scanner(System.in);

System.out.print("Enter a number : ");

int num = sc.nextInt();

if(num%7==0 || num%10==7)

System.out.println(num+" is BUZZ number.");

else

System.out.println(num+" is not BUZZ number.");

}

}

Output of the code:

Java program to convert to binary number to decimal number.

Conversion of binary number to decimal number and its vice versa is one of the most important concept in understanding computer logics and it designs. 

Binary number is expressed in base 2. It is made up of 0s or 1s.

Example of binary number = 10101

A bit is a single binary digit. The example given above has 5 bits.

Decimal number is expressed in base 10. We can use digits from 0 to 9.

Example of decimal number = 21

Below is the program to do the conversion from Binary to Decimal:

import java.util.Scanner;

public class BinaryToDecimal 

{

public static void main(String args[])

{

Scanner sc = new Scanner(System.in);

System.out.print("Enter a Binary number : ");

int binNum = sc.nextInt();

int temp = binNum;

int sum=0,i=0;

while(temp>0)

{

int rem = temp%10;

sum = sum+rem*(int)Math.pow(2,i);

temp = temp/10;

i++;

}

System.out.println("Decimal conversion of "+binNum+" = "+sum);

sc.close();

}

}

Java Program to print HAPPY HOLI

This is for all the coding geeks who want to wish their friends in their own style.

// Java program to print Happy Holi
class Happy_holi
{   
    public static void main (String[] args)
    {
        char ch = '@';
        for (int i = 1; i <= 51; i++)
        {
            if (i == 4 || i == 7 || i == 10 || i == 11 || i == 15 || i == 16 || i == 20 ||
                i == 21 || i == 24 || i == 27 || i == 32 || i == 35 || i == 38 || i == 39 ||
                i == 42 || i == 47 || i == 48 || i == 49 || i == 50)
                System.out.print(ch);
            else
                System.out.print(" ");
        }
    
        System.out.println();
        for (int i = 1; i <= 51; i++)
        {
            if (i == 4 || i == 7 || i == 9 || i == 12 || i == 14 || i == 17 || i == 19 ||
                i == 22 || i == 24 || i == 27 || i == 32 || i == 35 || i == 37 || i == 40 ||
                i == 42 || i == 48 ||i==49)
                System.out.print(ch);
            else
                System.out.print(" ");
        }
    
          System.out.println();
        for (int i = 1; i <= 51; i++)
        {
            if (i == 4 || i == 5 || i == 6 || i == 7 || i == 9 || i == 10 || i == 11 || i == 12 ||
                i == 14 || i == 15 || i == 16 || i == 19 || i == 20 || i == 21  || i == 25 ||
                i == 26 || i == 32 || i == 33 || i == 34 || i == 35 || i == 37 || i == 40 ||
                i == 42 || i == 48 ||i==49)
                System.out.print(ch);
            else
                System.out.print(" ");
        }
    
        System.out.println();
        for (int i = 1; i <= 51; i++)
        {
            if (i == 4 || i == 7 || i == 9 || i == 12 || i == 14 || i == 19 || i == 25 || i == 26 ||
                i == 32 || i == 35 || i == 37 || i == 40 || i == 42 || i == 48 || i == 49 )
                System.out.print(ch);
            else
                System.out.print(" ");
        }
    
        System.out.println();
        for (int i = 1; i <= 51; i++)
        {
            if (i == 4 || i == 7 || i == 9 || i == 12 || i == 14 || i == 19 || i == 25 || i == 26 ||
                i == 32 || i == 35 || i == 38 || i == 39 || i == 42 || i == 43 || i == 44 || i == 45 ||
                i == 47 || i == 48 || i == 49 || i == 50)
                System.out.print(ch);
            else
                System.out.print(" ");
        }
    }
}

Output: