ICSE Class 10 Computer Applications — 2025 Improvement

equals()

Reason — In Java, the equals() method compares the contents of two strings and returns a boolean value (true or false), whereas trim(), replace(), and concat() return new strings, not boolean values.

switch construct

Reason — The switch construct can be used to select and execute only the case that matches the required ice cream choice, skipping all other cases, which makes it suitable when only one specific ice cream needs to be selected from several options.

check() has return type int

Reason — In the method prototype int check(char ch, String s), the keyword int before the method name specifies that the method returns an integer value. The parameters char ch and String s are formal parameters, and the method is not a constructor as it has a return type.

round()

Reason — The round() method returns an int. Other methods like cbrt() and ceil() return double, while random() returns a double value between 0.0 and 1.0.

5

Reason — In the string "MONOPOLY", the character 'O' occurs at indexes 1, 3, and 5 (indexing starts from 0). The lastIndexOf('O') method returns the last occurrence of 'O', which is at index 5.

int amount = (int) valueINR;

Reason — The correct syntax to typecast a double to an int in Java is by placing (int) before the double variable, which converts it to an integer by removing its decimal part.

5 4

Reason — In System.out.print(lives--), the post-decrement operator (lives--) prints the current value of lives (which is 5) first, then decreases it to 4. The next System.out.print(lives) prints the updated value 4.

PROGRAM

Reason — In the string "JavaProgramming", indexing starts at 0. substring(4, 11) extracts characters from index 4 to 10, which is "Program". Calling .toUpperCase() converts it to "PROGRAM".

private

Reason — In Java, the private access specifier restricts a member’s visibility so it can be accessed only within the same class where it is declared.

false

Reason — The method Character.isLetterOrDigit('\n') checks whether the given character is a letter or a digit. The character '\n' represents a newline, which is neither a letter nor a digit, so the method returns false.

only 1

Reason — In Java, the main types of tokens are keywords, identifiers, literals, operators, and separators. A method is not considered a token; it is a block of code that performs a task.

Method prototype

Reason — In Java, a method prototype specifies the method’s access specifier, return type, name, and parameter list without including its body. The statement public void Accept(int a) shows these elements but does not contain a method body, so it is a method prototype.

False

Reason — The code declares a boolean variable flag with the value false, checks it in the if condition, and since it evaluates to false, the if block is skipped and the else block executes, printing False to the output.

isLetter(char)

Reason — The method isLetter(char) belongs to the Character class and is a static method, meaning it can be called using the class name without creating an object. The other methods (length(), nextLine(), substring(int)) are instance methods that require an object to be invoked.

jeev

Reason — In the array, the element at position 2 is "Rajeev". In Java, string indexing starts from 0, so index 0 = R, index 1 = a, and index 2 = j. Using substring(2) means we take all characters from index 2 to the end, giving "jeev".

-8

Reason — First, Math.ceil(-8.8) returns -8.0 because ceil() rounds a number up to the nearest integer (for negative numbers, “up” means closer to zero). Then, Math.round(-8.0) returns the integer -8, as round() converts a floating-point number to the nearest whole number.

x[2][2]=100;

Reason — In Java, array indexing starts from 0, so a 3 × 3 array has valid row and column indices 0, 1, and 2. The last element is at row index 2 and column index 2, so x[2][2] = 100; correctly assigns the value 100 to that element.

S[1][0]

Reason — In a two-dimensional array S[2][3], the first index represents the row and the second index represents the column, both starting from 0. Based on the given arrangement of storage devices, the element "Hard disk" is located in the second row (index 1) and first column (index 0), so its index is S[1][0].

11

Reason — The loop starts with k = 10 and runs while k >= 0. This includes both k = 10 and k = 0, so the values of k will be: 10, 9, 8, ..., 1, 0 — a total of 11 iterations.

3 1 4 2

Reason — To return the sum of first 10 natural numbers, we must follow the proper sequence of statements:

1. int sum = 0, i; – Declare the variables sum and i, and initialize sum to 0.
2. for(i=1; i<=10; i++) – Start the loop to go through numbers 1 to 10.
3. sum+=i; – Add the current number i to sum during each loop iteration.
4. return sum; – After the loop completes, return the total sum.

Math.pow(x, 10) + Math.pow(y, 10)

x *= --x + x-- + x
x = x * (--x + x-- + x)
x = 4 * (--x + x-- + x)
x = 4 * (3 + x-- + x)
x = 4 * (3 + 3 + x)
x = 4 * (3 + 3 + 2)
x = 4 * 8
x = 32

if (x == 'T' || x == 't') {
    System.out.print("Teacher");
} else {
    System.out.print("Student");
}

1  3  5  7  9

1. The loop control variable a is initialized to 1 and is incremented by 1 after each iteration until it attains the value 10.
2. The condition if (a % 2 == 0) tests whether a is an even number. If the condition is true, the continue statement transfers control to the next iteration of the loop, thereby skipping the print statement.
3. Consequently, only the odd values 1, 3, 5, 7, and 9 are displayed by the statement System.out.print(a + " ");.

Variable: Name

Methods: meow(), eat(), play()

100
60
20

The loop is executed 3 times.

• Initial value: k = 100 → printed, then reduced to 60.
• Second iteration: k = 60 → printed, then reduced to 20.
• Third iteration: k = 20 → printed, then reduced to -20.
• Loop stops when k < 10.

(a) The order of the array z[ ][ ] is 3 × 3.

(b) The value in z[2][0] is 7.

(a)

9

The method compareTo() compares two strings lexicographically by evaluating the Unicode value of each character from left to right until a mismatch is found.

1. 'R' (82) vs 'R' (82) → same.
2. 'O' (79) vs 'O' (79) → same.
3. 'S' (83) vs 'J' (74) → difference = 83 - 74 = 9.

Since a mismatch occurs at the third character, the comparison stops; therefore, the characters 'E' and 'A' are not compared.

Hence, the method returns 9.

(b)

LELICATE

The replace('D', 'L') method substitutes every occurrence of the character 'D' in the string "DEDICATE" with 'L', resulting in "LELICATE".

(a) In Java, each element of type char occupies 2 bytes of memory. The given array has 6 elements, therefore:

Total memory = 6 × 2 = 12 bytes.

(b)

true

• The element ch[4] contains the character '7'.
• The method Character.isDigit('7') returns true because '7' is a numeric digit.

(a)

Xavier     95

• A perform object ob1 is created using new perform(95, "Xavier").
• The constructor assigns m = 95 and name = "Xavier".
• The print() method outputs the name followed by spaces and then m.

(b) The constructor perform(int x, String y) accepts arguments, hence it is a parameterized constructor.

import java.util.Scanner;

class Hotel {
    String name;
    long mobno;
    int days;
    int bill;

    void input() {
        Scanner sc = new Scanner(System.in);
        System.out.print("Enter customer name: ");
        name = sc.nextLine();
        System.out.print("Enter mobile number: ");
        mobno = sc.nextLong();
        System.out.print("Enter number of days stayed: ");
        days = sc.nextInt();
    }

    void charge() {
        if (days <= 3) {
            bill = days * 1000;
        } else if (days <= 7) {
            bill = (3 * 1000) + (days - 3) * 900;
        } else {
            bill = (3 * 1000) + (4 * 900) + (days - 7) * 800;
        }
        bill += bill * 0.18;
    }

    void print() {
        System.out.println("Customer Name : " + name);
        System.out.println("Mobile Number : " + mobno);
        System.out.println("Total Bill    : Rs " + bill);
    }

    public static void main(String[] args) {
        Hotel h = new Hotel();
        h.input();
        h.charge();
        h.print();
    }
}

import java.util.Scanner;

public class RowProduct {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int[][] arr = new int[3][3];

        System.out.println("Enter 9 integers for the 3x3 array:");
        for (int i = 0; i < 3; i++) {
            for (int j = 0; j < 3; j++) {
                arr[i][j] = sc.nextInt();
            }
        }

        for (int i = 0; i < 3; i++) {
            int product = 1;
            for (int j = 0; j < 3; j++) {
                product *= arr[i][j];
            }
            System.out.println("Row " + i + " – " + product);
        }
    }
}

@@@  
@@@
@@@

import java.util.Scanner;

public class OverloadTransform {

    int transform(int n) {
        int sum = 0;
        while (n > 0) {
            int d = n % 10;
            sum += d;
            n /= 10;
        }
        return sum;
    }

    void transform(String s) {
        String str = s.toUpperCase();
        System.out.println(str);
    }

    void transform(char ch) {
        for (int i = 0; i < 3; i++) {
            for (int j = 0; j < 3; j++) {
                System.out.print(ch);
            }
            System.out.println();
        }
    }

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        OverloadTransform obj = new OverloadTransform();

        System.out.print("Enter an integer: ");
        int num = sc.nextInt();
        System.out.println("Sum of digits: " + obj.transform(num));

        sc.nextLine();
        System.out.print("Enter a string: ");
        String str = sc.nextLine();
        obj.transform(str);

        System.out.print("Enter a character: ");
        char ch = sc.next().charAt(0);
        obj.transform(ch);
    }
}

import java.util.Scanner;

public class SpecialString {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        System.out.print("Enter a string: ");
        String str = sc.nextLine().toUpperCase();

        int vowels = 0, consonants = 0;
        int len = str.length();

        for (int i = 0; i < len; i++) {
            char ch = str.charAt(i);
            if (ch >= 'A' && ch <= 'Z') {
                if (ch == 'A' 
                    || ch == 'E' 
                    || ch == 'I' 
                    || ch == 'O' 
                    || ch == 'U')
                    vowels++;
                else
                    consonants++;
            }
        }

        System.out.println("Number of vowels = " + vowels);
        System.out.println("Number of consonants = " + consonants);

        if (vowels == consonants)
            System.out.println("It is a Special String");
        else
            System.out.println("It is not a Special String");
    }
}

            N = 2396    N = 9316
First digit:   2         9
Last digit:    6         6
Sum:           8         15
Output: Sum is even  Sum is odd

import java.util.Scanner;

public class FirstLastSum {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        System.out.print("Enter a number: ");
        int n = sc.nextInt();

        int lastDigit = n % 10;
        int firstDigit = n;
        while (firstDigit >= 10) {
            firstDigit /= 10;
        }

        int sum = firstDigit + lastDigit;

        System.out.println("First digit: " + firstDigit);
        System.out.println("Last digit: " + lastDigit);
        System.out.println("Sum: " + sum);

        if (sum % 2 == 0)
            System.out.println("Sum is even");
        else
            System.out.println("Sum is odd");
    }
}

import java.util.Scanner;
public class LinearSearchArray {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int[] arr = new int[10];

        System.out.println("Enter 10 integers:");
        for (int i = 0; i < 10; i++) {
            arr[i] = sc.nextInt();
        }
        System.out.print("Enter the value to search: ");
        int key = sc.nextInt();
        int i = 0;

        for (i = 0; i < 10; i++) {
            if (arr[i] == key) {
                break;
            }
        }
        
        if (i < 10)
            System.out.println("Value found at position: " + (i + 1));
        else
            System.out.println("Value not found in the array");
    }
}