What the board asks
We went through the ISC board papers, question by question, and matched each question to a topic. Here is what was asked, how often, and what was never asked.
Computer Science: 180 topics in the 2027 syllabus, across 10 units. The board has asked 117 of them at least once. 63 were never asked in the papers we checked.
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CS8 Inheritance, Interfaces and Polymorphism
All the topics in Computer Science: Inheritance, Interfaces and Polymorphism
Asked topics first, the most asked at the top. Tap a topic to see what to write, the result, the years, and the real board questions.
13 topics shown
| # | Topic | Type | Marks | Times asked | Last asked | Status |
|---|---|---|---|---|---|---|
| 1 | Inheritance pair: subclass that computes by given rulesWrite the subclass header with extends, its data members, a parameterised constructor that passes the superclass values through super(...) and sets its own, the compute method applying every stated rate, condition or slab exactly, and the overriding show() that calls super.show() and prints the subclass results. | Program | 5 | 6 papers | 2026 | Asked |
| 2 | Interface versus class and versus abstract classGive a definition of an interface and at least two clear points of difference from a class (and from an abstract class): instantiation, kind of methods, kind of data members, keyword used, multiple implementation. | Comparison | 2 | 4 papers | 2026 | Asked |
| 3 | Interface rules: data members and methodsDefine an interface and state its rules: data members are implicitly public, static and final and must be initialised; methods are implicitly public and abstract (default and static methods allowed from Java 8); a class uses implements and must define every abstract method or be declared abstract. | Statement | 1 | 3 papers | 2026 | Asked |
| 4 | Inheritance pair: subclass using superclass arrays or methodsWrite the subclass whose method calls a superclass method (for example a factorial) or works on the superclass arrays (for example finding the highest mark), with the constructor through super(...) and a show() that calls super's display before its own output. | Program | 5 | 2 papers | 2019 | Asked |
| 5 | Abstract classes and abstract methodsDefine an abstract class and an abstract method, state that an abstract class cannot be instantiated, may mix abstract and concrete methods, and that a concrete subclass must override every abstract method. | Statement | 1 | 1 paper | 2025 improvement | Asked |
| 6 | Why interfaces: behaviour supplied by the user of a classState a use of interfaces (multiple inheritance of type, a contract the user implements) and explain with the syllabus example of a sorting class whose comparison is supplied by the end user; also explain the difference between the Java interface construct and the word interface meaning a class's set of method prototypes. | Give reason | 1 | 1 paper | 2024 | Asked |
| 7 | Inheritance terms: superclass, subclass, extends, typesDefine inheritance, superclass and subclass, name the keyword extends, state the is-a test for when a class should extend another, and name single, multilevel and hierarchical inheritance with a one-line example each. | Statement | 1 | 1 paper | 2023 | Asked |
| 8 | Class that extends a superclass and implements an interfaceWrite the class header with extends and implements, its data members, a constructor using super(...), the public implementation of each interface method using the interface constant, and show() calling super.show(). | Program | 5 | 1 paper | 2020 | Asked |
| 9 | Member access in a subclass; private, protected, publicState which superclass members a subclass can use directly for each access specifier (private, default, protected, public) and explain why protected suits data a subclass must read. | Give reason | 1 | never | Never asked | |
| 10 | The super keyword: constructor chaining and calling superclass methodsExplain and write super(...) as the first statement of a subclass constructor and super.method() to call the superclass version, and state the order in which constructors run. | Give reason | 1 | never | Never asked | |
| 11 | Overriding versus overloading; redefining variables in a subclassDistinguish method overriding (same signature in subclass, decided at run time) from overloading (same name, different parameters, decided at compile time), and explain what happens when a subclass declares a variable with the same name as a superclass variable (hiding). | Comparison | 2 | never | Never asked | |
| 12 | Output of code with overriding and dynamic bindingGiven a superclass reference holding a subclass object, write the exact output line by line, saying which version of each method runs and why. | Dry run / output | 2 | never | Never asked | |
| 13 | The class Object as the root of every classState that every Java class implicitly extends Object and name its commonly used methods (toString, equals) with what each does. | Statement | 1 | never | Never asked |
This list was made from the 2027 syllabus and checked with 9 board papers, including the 2027 specimen paper. It is not yet checked with the textbook.
The 10 topics Computer Science papers ask most
Counted on the board papers from 2018 to the 2027 specimen paper, which every unit has been checked against.
- 1.Principle of duality: state it and write the dualCS1 Boolean Algebra · asked 8 times since 2018
- 2.Complement of an expression using De Morgan's theoremCS1 Boolean Algebra · asked 8 times since 2018
- 3.Word problem to truth table and SOP or POSCS1 Boolean Algebra · asked 8 times since 2018
- 4.K-map reduction of a four-variable POS expressionCS1 Boolean Algebra · asked 8 times since 2018
- 5.Pre-order, in-order and post-order traversalCS9 Data Structures · asked 8 times since 2018
- 6.K-map reduction of a four-variable SOP expressionCS1 Boolean Algebra · asked 7 times since 2018
- 7.Read a tree: leaves, internal nodes, parent, siblings, degreeCS9 Data Structures · asked 7 times since 2018
- 8.Truth table to classify tautology, contradiction or contingencyCS1 Boolean Algebra · asked 6 times since 2018
- 9.Convert between cardinal and canonical formsCS1 Boolean Algebra · asked 6 times since 2018
- 10.Address of an element, row major and column majorCS6 Arrays and Strings · asked 6 times since 2018