ICSE Class 10 Computer Applications Sample Paper 2022 with Solutions

SECTION A

Question 1

Choose the correct answers to the questions from the given options. (Do not copy the question, Write the correct answer only.) [10]

(i) When primitive data type is converted to its corresponding object of its class, it is called as ___________. [1 Mark]
(a) Boxing
(b) Explicit type conversion
(c) Unboxing
(d) Implicit type conversion

Answer: (a) Boxing

When primitive data type is converted to its corresponding object of its class, it is called as Boxing.

Teacher's Note:
a) Boxing wraps a primitive value into a wrapper class object.
b) Do not confuse boxing with unboxing, which is the reverse process of converting an object back to a primitive type.

(ii) State the value of y after the following is executed:
char x='7';
y= Character.isLetter(x); [1 Mark]
(a) false
(b) 7
(c) true
(d) ‘7’

Answer: (a) false

The variable x stores the character '7', which is a digit, not a letter. Hence Character.isLetter(x) returns false into y.

Teacher's Note:
a) Character.isLetter() checks whether the specified character is a letter.
b) Students often confuse digit characters with alphabetic letters in wrapper class methods.

(iii) Give the output of the following string methods:
"MISSISSIPPI".indexOf('S')+ "MISSISSIPPI".lastIndexOf('I') [1 Mark]
(a) 10
(b) 12
(c) 20
(d) 11

Answer: (b) 12

"MISSISSIPPI".indexOf('S') returns 2, and "MISSISSIPPI".lastIndexOf('I') returns 10. Adding them gives 2 + 10 = 12.

Teacher's Note:
a) indexOf() returns the index of the first occurrence of the specified character, while lastIndexOf() returns the index of the last occurrence.
b) String indexing in Java always starts at 0.

(iv) Corresponding wrapper class of int data type is __________. [1 Mark]
(a) integer
(b) INTEGER
(c) Int
(d) Integer

Answer: (d) Integer

The Integer is the Wrapper class for the int primitive data type.

Teacher's Note:
a) Wrapper class names start with an uppercase letter corresponding to their primitive counterparts.
b) Note that for int and char, the wrapper classes are Integer and Character respectively, not Int or Char.

(v) Variable that is declared with in the body of a method is termed as: [1 Mark]
(a) Instance variable
(b) class variable
(c) Local variable
(d) Argument variable

Answer: (c) Local variable

Variable that is declared within the body of a method is called a local variable as they are accessible locally in the scope of the method.

Teacher's Note:
a) Local variables must be initialized before use as they do not receive default values.
b) Their scope is restricted to the method or block in which they are declared.

(vi) Identify the correct array declaration statement: [1 Mark]
(a) int a[10];
(b) int a[]=new int[10];
(c) int arr[i]=10;
(d) int a[10]=new int[];

Answer: (b) int a[]=new int[10];

While declaring an array the array name along with the new operator and size of the array is to be specified.

Teacher's Note:
a) Java does not allow specifying the size of the array in the left-hand side declaration brackets.
b) Memory allocation for arrays is done dynamically using the new operator.

(vii) A variable that is bounded to the object itself is called as: [1 Mark]
(a) Instance variable
(b) class variable
(c) Local variable
(d) Argument variable

Answer: (a) Instance variable

An Instance variable is bounded to the object itself as it carries different values for different objects.

Teacher's Note:
a) Instance variables are declared inside a class but outside any method.
b) They get default values (like 0, null, false) if not explicitly initialized.

(viii) The access modifier that gives most accessibility is: [1 Mark]
(a) private
(b) public
(c) protected
(d) package

Answer: (b) public

As the name suggests, the public access specifier creates members that are accessible to all others.

Teacher's Note:
a) public members can be accessed from any class across any package.
b) private is the most restrictive access modifier, accessible only within the same class.

(ix) Give the output of the following code:
String A ="26.0", B="74.0";
double C= Double .parseDouble(A);
double D = Double .parseDouble(B);
System.out.println((C+D)); [1 Mark]
(a) 26
(b) 74
(c) 100.0
(d) 2674

Answer: (c) 100.0

double C = Double.parseDouble(A); gives C as 26.0, double D = Double.parseDouble(B); gives D as 74.0, and C+D gives 100.0.

Teacher's Note:
a) parseDouble() converts a string representation of a number into a primitive double value.
b) Since C and D are of type double, their sum is printed as a floating-point number (100.0).

(x) Wrapper classes are available in __________ package. [1 Mark]
(a) java.io
(b) java.util
(c) java.lang
(d) java.awt

Answer: (c) java.lang

The Wrapper classes in java are available in java.lang package.

Teacher's Note:
a) The java.lang package is imported implicitly in all Java programs.
b) It includes fundamental classes such as Object, String, Math, and all Wrapper classes.

SECTION B

Question 2 [10 Marks]
Define a class to declare an integer array of size n and accept the elements into the array. Search for an element input by the user using linear search technique, display the element if it is found, otherwise display the message “NO SUCH ELEMENT”.

Answer:
import java.util.Scanner;
class LinearSearch
{
    public static void main(String args[])
    {
        int c, n, search, array[];
        Scanner in = new Scanner(System.in);
        System.out.println("Enter number of elements");
        n = in.nextInt();
        array = new int[n];
        System.out.println("Enter those " + n + " elements");
        for (c = 0; c < n; c++)
            array[c] = in.nextInt();
        System.out.println("Enter value to find");
        search = in.nextInt();
        for (c = 0; c < n; c++)
        {
            if (array[c] == search) /* Searching element is present */
            {
                System.out.println(array[c]);
                break;
            }
        }
        if (c == n) /* Element to search isn't present */
            System.out.println("NO SUCH ELEMENT");
    }
}

Teacher's Note:
a) Linear search checks each element of the array sequentially until the desired element is found or the array ends.
b) Note that the official answer key prints search + " No such element", but the question specifies displaying "NO SUCH ELEMENT". The code above outputs the exact string required by the question prompt.

Question 3 [10 Marks]
Define a class to declare a character array of size ten, accept the character into the array and perform the following:
- Count the number of uppercase letters in the array and print.
- Count the number of vowels in the array and print.

Answer:
import java.util.Scanner;
public class CountUpperLower
{
    public static void main(String[] args)
    {
        Scanner sc = new Scanner(System.in);
        int upperCase = 0;
        int vowels = 0;
        char chh, ch;
        System.out.println("Input some characters...");
        char[] a = sc.next().toCharArray();
        for(int i = 0; i < a.length; i++)
        {
            chh = a[i];
            System.out.print(a[i]);
            if(chh >= 'A' && chh <= 'Z')
                upperCase++;
            ch = Character.toUpperCase(chh);
            if(ch == 'A' || ch == 'E' || ch == 'I' || ch == 'O' || ch == 'U')
                vowels++;
        }
        System.out.println("Count of uppercase letters :" + upperCase);
        System.out.println("Count of vowels :" + vowels);
    }
}

Teacher's Note:
a) The program uses Character wrapper methods and ASCII range checks to identify uppercase letters and vowels.
b) Note that the official key declaration char[10] a contains a syntax error in Java; array declaration should be char[] a or a = new char[10]. The corrected syntax is applied in the solution.

Question 4 [10 Marks]
Define a class to declare an array of size 20 of double datatype, accept the elements into the array and perform the following:
- Calculate and print the sum of all the elements.
- Calculate and print the highest value of the array.

Answer:
import java.util.Scanner;
public class MaxSum
{
    public static void main(String args[])
    {
        Scanner in = new Scanner(System.in);
        double arr[] = new double[20];
        System.out.println("Enter 20 numbers:");
        for (int i = 0; i < 20; i++)
        {
            arr[i] = in.nextDouble();
        }
        double max = arr[0], sum = 0.0;
        for (int i = 0; i < arr.length; i++)
        {
            if (arr[i] > max)
                max = arr[i];
            sum += arr[i];
        }
        System.out.println("Largest Number = " + max);
        System.out.println("Sum = " + sum);
    }
}

Teacher's Note:
a) Since the array elements are of type double, both the maximum variable and sum variable are declared as double.
b) The official key initializes sum as an integer (int sum = 0), which can cause a type mismatch when adding double elements. It is corrected to double sum = 0.0.

Question 5 [10 Marks]
Define a class to accept two strings, convert them into uppercase, check and display whether two strings are equal or not, if the two strings are not equal, print the string with the highest length or print the message both the strings are of equal length.

Answer:
import java.util.*;
public class Strings
{
    public static void main(String [] args)
    {
        String s1 = "", s2 = "";
        Scanner sc = new Scanner(System.in);
        System.out.println("Enter two strings :");
        s1 = sc.nextLine();
        s2 = sc.nextLine();
        s1 = s1.toUpperCase();
        s2 = s2.toUpperCase();
        if (!s1.equals(s2))
        {
            if (s1.length() > s2.length())
                System.out.println(s1);
            else if (s2.length() > s1.length())
                System.out.println(s2);
            else
                System.out.println("Both the strings are of equal length.");
        }
        else
        {
            System.out.println("Strings are equal");
        }
    }
}

Teacher's Note:
a) The program uses equals() and length() methods of the String class after converting both inputs to uppercase.
b) The official key misses handling the case where unequal strings have the same length; an explicit check and message for equal lengths have been added for completeness.

Question 6 [10 Marks]
Define a class to accept a string, convert it into lowercase and check whether the string is a palindrome or not.
A palindrome is a word which reads the same backward as forward.
Example:
madam, racecar etc.

Answer:
import java.util.Scanner;
public class Palindrome
{
    public static void main(String args[])
    {
        String a, b = "";
        Scanner s = new Scanner(System.in);
        System.out.print("Enter the string you want to check:");
        a = s.nextLine();
        a = a.toLowerCase();
        int n = a.length();
        for(int i = n - 1; i >= 0; i--)
        {
            b = b + a.charAt(i);
        }
        if(a.equalsIgnoreCase(b))
        {
            System.out.println("The string is palindrome.");
        }
        else
        {
            System.out.println("The string is not palindrome.");
        }
    }
}

Teacher's Note:
a) A palindrome string reads identically forwards and backwards.
b) Reversing the string using charAt() inside a decrementing loop is the standard approach taught at the ICSE level.

Question 7 [10 Marks]
Define a class to accept and store 10 strings into the array and print the strings with even number of characters.

Answer:
import java.util.*;
public class Strings
{
    public static void main(String[] args)
    {
        Scanner sc = new Scanner(System.in);
        String[] strArray = new String[10];
        System.out.println("Enter 10 Strings :");
        for (int i = 0; i < 10; i++)
            strArray[i] = sc.nextLine();
        for (int i = 0; i < 10; i++)
        {
            if (strArray[i].length() % 2 == 0)
                System.out.println(strArray[i]);
        }
    }
}

Teacher's Note:
a) The length() method determines the number of characters in each string, and the modulus operator checks if the length is even.
b) The official marking scheme specimen code loops up to 3 instead of 10; it has been corrected to 10 to match the question requirement.