ICSE Class 10 Computer Applications — 2012 Paper

1. int
2. array

(b) Give one point of difference between unary and binary operators.

unary operators operate on a single operand whereas binary operators operate on two operands.

(c) Differentiate between call by value or pass by value and call by reference or pass by reference.

Call by value	Call by reference
Values of actual parameters are copied to formal parameters.	Reference of actual parameters is passed to formal parameters.
Changes made to formal parameters are not reflected back to actual parameters.	Changes made to formal parameters are reflected back to actual parameters.

(d) Write a Java expression for:

$\sqrt{2as + u^2}$

Math.sqrt(2 * a * s + u * u)

(e) Name the type of error (syntax, runtime or logical error) in each case given below:

1. Division by a variable that contains a value of zero.
2. Multiplication operator used when the operation should be division.
3. Missing semicolon.

1. Runtime error
2. Logical error
3. syntax error

class Number {
    int a;

    public Number() {
        a = 0;
    }

    public Number(int x) {
        a = x;
    }
}

(b) Complete the code below to create an object of Scanner class:

    Scanner sc = ____ Scanner(__________);

Scanner sc = new Scanner(System.in);

(c) What is an array? Write a statement to declare an integer array of 10 elements.

An array is a structure to store a number of values of the same data type in contiguous memory locations. The following statement declares an integer array of 10 elements:

int arr[] = new int[10];

(d) Name the search or sort algorithm that:

1. Makes several passes through the array, selecting the next smallest item in the array each time and placing it where it belongs in the array.
2. At each stage, compares the sought key value with the key value of the middle element of the array.

1. Selection Sort
2. Binary Search

(e) Differentiate between public and private modifiers for members of a class.

public modifier makes the class members accessible both within and outside their class whereas private modifier makes the class members accessible only within the class in which they are declared.

x = true
y = 36

The ternary operator (a > b)? true : false returns true as its condition a > b is true so it returns its first expression that is true.

The ternary operator (a < b)? a : b returns b as its condition a < b is false so it returns its second expression that is b. Value of b is 36 so y also becomes 36.

(b) State the values of n and ch.

char c = 'A';
int n = c + 1;
char ch = (char)n;

Value of n is 66 and ch is B.

int n = c + 1, here due to implicit conversion, 'A' will be converted to its ASCII value 65. 1 is added to it making the value of n 66.

char ch = (char)n, here through explicit conversion 66 is converted to its corresponding character that is 'B' so value of ch becomes B.

(c) What will be the result stored in x after evaluating the following expression?

int x = 4;
x += (x++) + (++x) + x;

    x += (x++) + (++x) + x
⇒ x = x + ((x++) + (++x) + x)
⇒ x = 4 + (4 + 6 + 6)
⇒ x = 4 + 16
⇒ x = 20

(d) Give output of the following program segment:

double x = 2.9, y = 2.5;
System.out.println(Math.min(Math.floor(x), y));
System.out.println(Math.max(Math.ceil(x), y));

2.0
3.0

Math.floor(2.9) gives 2.0. Math.min(2.0, 2.5) gives 2.0.

Math.ceil(2.9) gives 3.0. Math.max(3.0, 2.5) gives 3.0.

(e) State the output of the following program segment:

String s = "Examination";
int n = s.length();
System.out.println(s.startsWith(s.substring(5, n)));
System.out.println(s.charAt(2) == s.charAt(6));

false
true

Putting the value of n in s.substring(5, n), it becomes s.substring(5, 11). This gives "nation". As s does not start with "nation" so s.startsWith(s.substring(5, n)) returns false.

s.charAt(2) is a and s.charAt(6) is also a so both are equal

(f) State the method that:

1. Converts a string to a primitive float data type.
2. Determines if the specified character is an uppercase character.

1. Float.parseFloat()
2. Character.isUpperCase()

(g) State the data type and values of a and b after the following segment is executed:

String s1 = "Computer", s2 = "Applications"
a = (s1.compareTo(s2));
b = (s1.equals(s2));

Data type of a is int and value is 2. Data type of b is boolean and value is false.

(h) What will the following code output:

String s = "malayalam";
System.out.println(s.indexOf('m'));
System.out.println(s.lastIndexOf('m'));

0
8

The first m appears at index 0 and the last m appears at index 8.

(i) Rewrite the following program segment using while instead of for statement.

int f = 1, i;
for(i = 1; i <= 5; i++){
    f *= i;
    System.out.println(f);
}

int f = 1, i;
while (i <= 5) {
    f *= i;
    System.out.println(f);
    i++;
}

(j) In the program given below, state the name and the value of the:

1. method argument or argument variable
2. class variable
3. local variable
4. instance variable

class MyClass{
    static int x = 7;
    int y = 2;
    public static void main(String args[]){
        MyClass obj = new MyClass();
        System.out.println(x);
        obj.sampleMethod(5);
        int a = 6;
        System.out.println(a);
    }
    void sampleMethod(int n){
        System.out.println(n);
        System.out.println(y);
    }
}

1. Method argument/Argument variable is n
2. Class variable is x
3. Local variable is a
4. Instance variable is y

import java.util.Scanner;

public class Library
{
    private int accNum;
    private String title;
    private String author;
    
    void input() {
        Scanner in = new Scanner(System.in);
        System.out.print("Enter book title: ");
        title = in.nextLine();
        System.out.print("Enter author: ");
        author = in.nextLine();
        System.out.print("Enter accession number: ");
        accNum = in.nextInt();
    }
    
    void compute() {
        Scanner in = new Scanner(System.in);
        System.out.print("Enter number of days late: ");
        int days = in.nextInt();
        int fine = days * 2;
        System.out.println("Fine = Rs." + fine);
    }
    
    void display() {
        System.out.println("Accession Number\tTitle\tAuthor");
        System.out.println(accNum + "\t\t" + title + "\t" + author);
    }
    
    public static void main(String args[]) {
        Library obj = new Library();
        obj.input();
        obj.display();
        obj.compute();
    }
}

import java.util.Scanner;

public class KboatIncomeTax
{
    public static void main(String args[]) {
        Scanner in = new Scanner(System.in);
        System.out.print("Enter Gender(male/female): ");
        String gender = in.nextLine();
        System.out.print("Enter Age: ");
        int age = in.nextInt();
        System.out.print("Enter Taxable Income: ");
        double ti = in.nextDouble();
        double tax = 0.0;

        if (age > 65 || gender.equalsIgnoreCase("female")) {
            System.out.print("Wrong Category");
        }
        else {
            if (ti <= 160000)
                tax = 0;
            else if (ti <= 500000)
                tax = (ti - 160000) * 10 / 100;
            else if (ti <= 800000)
                tax = 34000 + ((ti - 500000) * 20 / 100);
            else
                tax = 94000 + ((ti - 800000) * 30 / 100);
                
            System.out.println("Tax Payable: " + tax);
        }      
    }
}

import java.util.Scanner;

public class KboatLetterSeq
{
    public static void main(String args[]) {
        Scanner in = new Scanner(System.in);
        System.out.print("Enter string: ");
        String s = in.nextLine();
        String str = s.toUpperCase();
        int count = 0;
        int len = str.length();
        
        for (int i = 0; i < len - 1; i++) {
            if (str.charAt(i) == str.charAt(i + 1))
                count++;
        }
        
        System.out.println("Double Letter Sequence Count = " + count);
        
    }
}

public class KboatPolygon
{
    public void polygon(int n, char ch) {
        for (int i = 1; i <= n; i++) {
            for (int j = 1; j <= n; j++) {
                System.out.print(ch);
            }
            System.out.println();
        }
    }
    
    public void polygon(int x, int y) {
        for (int i = 1; i <= x; i++) {
            for (int j = 1; j <= y; j++) {
                System.out.print('@');
            }
            System.out.println();
        }
    }
    
    public void polygon() {
        for (int i = 1; i <= 3; i++) {
            for (int j = 1; j <= i; j++) {
                System.out.print('*');
            }
            System.out.println();
        }
    }
    
    public static void main(String args[]) {
        KboatPolygon obj = new KboatPolygon();
        obj.polygon(2, 'o');
        System.out.println();
        obj.polygon(2, 5);
        System.out.println();
        obj.polygon();
    }
}

import java.util.Scanner;

public class KboatFibonacciNDigitSum
{
    public static void main(String args[]) {
        Scanner in = new Scanner(System.in);
        System.out.println("1. Fibonacci Series");
        System.out.println("2. Sum of digits");
        System.out.print("Enter your choice: ");
        int ch = in.nextInt();

        switch (ch) {
            case 1:
            int a = 0, b = 1;
            System.out.print(a + " " + b);
            for (int i = 3; i <= 10; i++) {
                int term = a + b;
                System.out.print(" " + term);
                a = b;
                b = term;
            }
            break;

            case 2:
            System.out.print("Enter number: ");
            int num = in.nextInt();
            int sum = 0;
            while (num != 0) {
                sum += num % 10;
                num /= 10;
            }
            System.out.println("Sum of Digits " + " = " + sum);
            break;

            default:
            System.out.println("Incorrect choice");
            break;
        }
    }
}

import java.util.Scanner;

public class KboatStdCodes
{
    public static void main(String args[]) {
        final int SIZE = 10;
        Scanner in = new Scanner(System.in);
        String cities[] = new String[SIZE];
        String stdCodes[] = new String[SIZE];
        System.out.println("Enter " + SIZE + 
                 " cities and their STD codes:");
        
        for (int i = 0;  i < SIZE; i++) {
            System.out.print("Enter City Name: ");
            cities[i] = in.nextLine();
            System.out.print("Enter its STD Code: ");
            stdCodes[i] = in.nextLine();
        }
        
        System.out.print("Enter name of city to search: ");
        String city = in.nextLine();
        
        int idx;
        for (idx = 0;  idx < SIZE; idx++) {
            if (city.compareToIgnoreCase(cities[idx]) == 0) {
                break;
            }
        }
        
        if (idx < SIZE) {
            System.out.println("Search Successful");
            System.out.println("City: " + cities[idx]);
            System.out.println("STD Code: " + stdCodes[idx]);
        }
        else {
            System.out.println("Search Unsuccessful");
        }
    }
}