ICSE Class 10 Computer Applications — 2023 Paper

Inheritance

Reason — Inheritance enables new classes to receive or inherit the properties and methods of existing classes.

logical

Reason — Logical operators operate only on boolean operands and are used to construct complex decision-making expressions. Logical AND && operator evaluates to true only if both of its operands are true.

nextLine()

Reason — nextLine() reads the input till the end of line so it can read a full sentence including spaces.

import

Reason — import keyword is used to import built-in and user-defined packages into our Java program.

4.0

Reason — Math.ceil method returns the smallest double value that is greater than or equal to the argument and Math.sqrt method returns the square root of its argument as a double value. Thus the given expression is evaluated as follows:

Math.sqrt(Math.ceil (15.3))
= Math.sqrt(16.0)
= 4.0

break

Reason — The absence of break statement leads to fall through situation in switch case statement.

infinite

Reason — The given loop is an example of infinite loop as for each consecutive iteration of for loop, the value of i will be updates as follows:

Since i will never be '0', the loop will execute infinitely.

char check (int x)

Reason — The prototype of a function is written in the given syntax:

return_type method_name(arguments)

Thus, the method has the prototype given below:

char check (int x)

1

Reason — A method can return only one value.

20 22

Reason — The values of strings P and Q are converted into integers using the Integer.parseInt() method and stored in int variables a and b, respectively.
When the statement System.out.println(a + " " + b) is executed, first the operation a + " " is performed. Here, int variable a is converted to a string and a space is concatenated to it resulting in "20 ".
After this, the operation "20 " + b is performed resulting in 20 22 which is printed as the output.

concat(String)

Reason — concat() method is used to join two strings. Its syntax is as follows:

String1.concat(String2)

POS

Reason — The substring() method returns a substring beginning from the startindex and extending to the character at endIndex - 1. Since a string index begins at 0, the character at index 3 is 'P' and the character at index 5 (6-1 = 5) is 'S'. Thus, "POS" is extracted.

explicit

Reason — In explicit type conversion, the data gets converted to a type as specified by the programmer. Here, the float value 32.8 is being converted to int type by the programmer, explicitly.

java byte code

Reason — Java compiler converts Java source code into an intermediate binary code called Bytecode after compilation.

Syntax

Reason — Syntax Errors occur when we violate the rules of writing the statements of the programming language. Missing a semicolon in a statement is a syntax error.

20
40

Reason — Since n = 10, case 10 will be executed. It prints 20 (10 * 2) on the screen. Since break statement is missing, the execution falls through to the next case. Case 4 prints 40 (10 * 4) on the screen. Now the control finds the break statement and the control comes out of the switch statement.

Pure method

Reason — A method which does not modify the value of variables is termed as a pure method.

Unboxing

Reason — When an object of a Wrapper class is converted to its corresponding primitive data type, it is called as unboxing.

16 bits

Reason — A char data type occupies 2 bytes in the memory.

1 byte = 8 bits
2 bytes = 8 * 2 = 16 bits

Static method

Reason — Method which is a part of a class rather than an instance of the class is termed as Static method.

Math.pow(a + b, x)

The given expression is evaluated as follows:

x *= --x + x++ + x (x = 4)
x *= 3 + x++ + x (x = 3)
x *= 3 + 3 + x (x = 4)
x *= 3 + 3 + 4 (x = 4)
x *= 10 (x = 4)
x = x * 10 (x = 4)
x = 4 * 10
x = 40

for(int x = 9; x >= 0; x--)
{
    System.out.print(x);
}

(a) Character.toUpperCase ('a')

A

In Java, the Character.toUpperCase(char ch) method is used to convert a given character to its uppercase equivalent, if one exists. So, the output is uppercase 'A'.

(b) Character.isLetterOrDigit('#')

false

Character.isLetterOrDigit() method returns true if the given character is a letter or digit, else returns false. Since, hash (#) is neither letter nor digit, the method returns false.

int m = 400;
double ch = 0.0;
if(m > 300)
    ch = (m / 10.0) * 2;
else
    ch = (m / 20.0) - 2;

9
2

Step by step explanation of the code:

1. int n = 4279; — Initializes the integer n with the value 4279.
2. int d; — Declares an integer variable d without initializing it. It will be used to store the individual digits.

Now, let's go through the loop:

The while loop continues as long as n is greater than 0:

• d = n % 10; — This line calculates the remainder when n is divided by 10 and stores it in d. In the first iteration, d will be 9 because the remainder of 4279 divided by 10 is 9.
• System.out.println(d); — This line prints the value of d. In the first iteration, it will print 9.
• n = n / 100; — This line performs integer division of n by 100. In the first iteration, n becomes 42. (Remember, it is integer division so only quotient is taken and fractional part is discarded.)

The loop continues, and in the second iteration:

• d = n % 10; — d will now be 2 because the remainder of 42 divided by 10 is 2.
• System.out.println(d); — It prints 2.
• n = n / 100; — n becomes 0 because 42 divided by 100 is 0. Since n is no longer greater than 0, the loop terminates.

(a) "COMMENCEMENT".lastIndexOf('M')

8

(a) 7

(b) 72

(a) Object.

(b) Constructor.

The value of n is 105.

import java.util.Scanner;

public class Student
{
    private String name;
    private int age;
    private double mks;
    private String stream;
    
    public void accept() 
    {
        Scanner in = new Scanner(System.in);
        System.out.print("Enter student name: ");
        name = in.nextLine();
        System.out.print("Enter age: ");
        age = in.nextInt();
        System.out.print("Enter marks: ");
        mks = in.nextDouble();
    }
    
    public void allocation() 
    {
        if (mks < 75)
            stream = "Try again";
        else if (mks < 200)
            stream = "Arts and Animation";
        else if (mks < 300)
            stream = "Commerce and Computer";
        else
            stream = "Science and Computer";
    }
    
    public void print() 
    {
        System.out.println("Name: " + name);
        System.out.println("Age: " + age);
        System.out.println("Marks: " + mks);
        System.out.println("Stream allocated: " + stream);
    }
    
    public static void main(String args[]) {
        Student obj = new Student();
        obj.accept();
        obj.allocation();
        obj.print();
    }
}

import java.util.Scanner;

public class KboatCharBubbleSort
{
    public static void main(String args[]) 
    {
        Scanner in = new Scanner(System.in);
        char ch[] = new char[10];
        System.out.println("Enter 10 characters:");
        for (int i = 0;  i < ch.length; i++) {
            ch[i] = in.nextLine().charAt(0);
        }

        System.out.println("Original Array");
        for (int i = 0;  i < ch.length; i++) {
            System.out.print(ch[i] + " ");
        }
        
        //Bubble Sort
        for (int i = 0; i < ch.length - 1; i++) {
            for (int j = 0; j < ch.length - 1 - i; j++) {
                if (ch[j] > (ch[j + 1])) {
                    char t = ch[j];
                    ch[j] = ch[j + 1];
                    ch[j + 1] = t;
                }
            }
        }
        
        System.out.println("\nSorted Array");
        for (int i = 0;  i < ch.length; i++) {
            System.out.print(ch[i] + " ");
        }
    }
}

1  1  1  1
2  2  2  2
3  3  3  3
4  4  4  4
5  5  5  5

void print(int n) - To check whether the number is a lead number. A lead number is the one whose sum of even digits are equal to sum of odd digits.

e.g. 3669
odd digits sum = 3 + 9 = 12
even digits sum = 6 + 6 = 12
3669 is a lead number.

import java.util.Scanner;

public class KboatMethodOverload
{
    public void print()
    {
        for(int i = 1; i <= 5; i++) 
        {
            for(int j = 1; j <= 4; j++)
            {
                System.out.print(i + " ");
            }
        System.out.println();
        }
    }
    
    public void print(int n)
    {
        int d = 0;
        int evenSum = 0;
        int oddSum = 0;
        while( n != 0)
        {
            d = n % 10;
            if (d % 2 == 0)
                    evenSum += d;
                else
                    oddSum += d;
            n = n / 10;
        }
        
        if(evenSum == oddSum)
            System.out.println("Lead number");
        else
            System.out.println("Not a lead number");
    }
    
    public static void main(String args[]) 
    {
        KboatMethodOverload obj = new KboatMethodOverload();
        Scanner in = new Scanner(System.in);
        
        System.out.println("Pattern: ");
        obj.print();
        
        System.out.print("Enter a number: ");
        int num = in.nextInt();
        obj.print(num);
    }
}

import java.util.Scanner;

public class KboatCount
{
   public static void main(String args[]) 
   {
        Scanner in = new Scanner(System.in);
        System.out.println("Enter a string:");
        String str = in.nextLine();
             
        int len = str.length();

        int ac = 0;
        int sc = 0;
        int dc = 0;
        char ch;

        for (int i = 0; i < len; i++) {
            ch = str.charAt(i);
            if (Character.isLetter(ch))  
                ac++;    
            else if (Character.isDigit(ch))
                dc++;
            else if (!Character.isWhitespace(ch))
                sc++;
        }
        
        System.out.println("No. of Digits = " + dc);
        System.out.println("No. of Alphabets = " + ac);
        System.out.println("No. of Special Characters = " + sc);
        
    }
}

import java.util.Scanner;

public class KboatLinearSearch
{
    public static void main(String args[]) 
    {
        Scanner in = new Scanner(System.in);
        
        double arr[] = new double[20];
        int l = arr.length;
        int i = 0;
        
        System.out.println("Enter array elements: ");
        for (i = 0; i < l; i++) 
        {
            arr[i] = in.nextDouble();    
        }
        
        System.out.print("Enter the number to search: ");
        double n = in.nextDouble();
        
        for (i = 0; i < l; i++) 
        {
            if (arr[i] == n) 
            {
                break;
            }
        }
        
        if (i == l) 
        {
            System.out.println("Not found");
        }
        else 
        {
            System.out.println(n + " found at index " + i);
        }
    }
}

import java.util.Scanner;

public class KboatDigitSum
{
    public static void main(String args[]) 
    {
        Scanner in = new Scanner(System.in);
        int oneSum = 0, twoSum = 0, d = 0;
        int arr[] = new int[10];
        System.out.println("Enter 10 numbers");
        int l = arr.length;
        
        for (int i = 0; i < l; i++) 
        {
            arr[i] = in.nextInt();
        }
        
        for (int i = 0; i < l; i++) 
        {
            if(arr[i] >= 0 && arr[i] < 10 )
                oneSum += arr[i];
            else if(arr[i] >= 10 && arr[i] < 100 )
                twoSum += arr[i];
        }
        
        System.out.println("Sum of 1 digit numbers = "+ oneSum);
        System.out.println("Sum of 2 digit numbers = "+ twoSum);
        
    }
}