ICSE Computer Applications notes: one revision sheet for every chapter.

Recursion is not in the 2027 Computer Applications syllabus, so it has no sheet here. Each unit is explained with its marks pattern on the ICSE Computer Applications syllabus page.

Chapter 3: User-defined methods

static int area(int s) { return s * s; }
static int area(int l, int b) { return l * b; }
static double area(double r) { return 3.14 * r * r; }
// in main:
System.out.println(area(5) + " " + area(4, 6)
                   + " " + area(2.0));

// Output: 25 24 12.56

Overloading programs in board format are worked on user-defined methods and overloading.

Chapter 4: Constructors

class Ticket {
    String name;
    int seats;
    Ticket() { name = "Guest"; seats = 1; }
    Ticket(String n, int s) { name = n; seats = s; }
}
// in main:
Ticket t1 = new Ticket();
Ticket t2 = new Ticket("Asha", 3);
System.out.println(t1.name + " " + t1.seats + " "
                   + t2.name + " " + t2.seats);

// Output: Guest 1 Asha 3

The slip: writing void before a constructor. It then becomes an ordinary method and never runs on new. More on ICSE constructor questions.

Chapter 5: Library classes

String s = "42";
int n = Integer.parseInt(s) + 8;
Integer boxed = n;              // autoboxing
char c = 'g';
System.out.println(n + " " + Character.toUpperCase(c)
    + " " + Character.isDigit('7') + " " + (boxed + 1));

// Output: 50 G true 51

Every wrapper method in the syllabus, with its return type, is on wrapper and library classes.

Chapter 6: Encapsulation

class Account {
    private double balance;
    public void deposit(double amt) {
        if (amt > 0) balance += amt;
    }
    public double getBalance() { return balance; }
}
// in main:
Account acc = new Account();
acc.deposit(500);
acc.deposit(-200);
System.out.println(acc.getBalance());

// Output: 500.0

Scope questions with worked examples are on encapsulation and access specifiers.

1. Tuesday: the sheet, built together

   At the 5:30 PM IST class the teacher builds the chapter's sheet on screen with the group, asking each student to define a term before it is written down, then runs the example in BlueJ.

2. A timed Section A set

   Ten short questions from that chapter only: definitions, outputs, a difference, an error to find. Answers are marked on screen against the way the board credits them.

3. Wednesday: one full program

   At the 8:00 PM IST class each student writes a Section B program from the chapter, with comments and a variable description, and the teacher reads it line by line.

4. Doubt time before moving on

   The last part of Wednesday is kept for questions on any earlier chapter, so a gap is caught before the next chapter depends on it.

5. Full papers from December

   When all eight chapters are done, the batch moves to complete two-hour mock papers marked like the board, and each mistake is sent back to the sheet it came from.

With no more than six students, every definition and every program gets read by the teacher, not sampled.