Q2. What is inside each unit?
Eight units, with what each contains and how the paper asks about it
The syllabus lists topics; the paper asks questions. This is the mapping between the two, which is what a student actually needs.
Unit 1 · the most examined unit in the book
Revision of Class IX syllabus
Object-oriented ideas, the elementary concept of objects and classes, values and data types, operators in Java and their precedence, input in Java, the mathematical library methods, conditional constructs, iterative constructs and nested loops. Nothing here is new, and everything here is examined: Section A's output-prediction and loop-count questions are built from this unit, and every Section B program assumes it. Treat it as the foundation it is.
Unit 2
Class as the basis of all computation
Objects and classes, the class as a user-defined data type, primitive and composite data types, objects as instances of a class with state and behaviour. The paper asks the student to read a small class definition and say what it models, and to distinguish primitive from composite. Short in pages, and the conceptual key to the next two units.
Unit 3
User-defined methods
The syntax of a method, the ways of invoking one, pure and impure methods, actual and formal parameters, the return statement, using multiple methods in a class, and method overloading. Section B's favourite format lives here: a class skeleton with named data members and method signatures, where the student must write the methods that make it work.
Unit 4
Constructors
What a constructor is, its characteristics, the types, default and parameterised, the uses of constructors, and the difference between a constructor and a method. A reliable two-mark difference question in Section A, and the reason a Section B class compiles, since the paper's class skeletons usually require one.
Unit 5
Library classes
The wrapper classes and their methods, converting between strings and numbers, character methods such as testing for a letter or a digit and changing case, and autoboxing and unboxing. Section A asks for the output of a wrapper or character method more often than students expect; Section B uses them inside string and menu programs.
Unit 6
Encapsulation
Access specifiers, private, public, protected and default, the visibility rules for each, and the scope of variables: instance, class, local and argument. The unit that explains why a program will or will not compile, and a steady source of Section A definitions and differences. It rarely produces a whole Section B program but shapes how every one of them is written.
Unit 7 · Section B territory
Arrays
Single and double dimensional arrays, declaration, initialisation, accepting data, and the search techniques, linear and binary, along with the sort techniques that follow from them. Arrays produce a Section B program in almost every paper: find, count, sum, search, sort, or fill a two-dimensional table. This unit gets the most Wednesdays in our batch for that reason.
Unit 8 · Section B territory
String handling
The String class and its methods, extracting and modifying characters of a string, and implementing string methods by hand. The other guaranteed Section B program: reverse a word, test a palindrome, count vowels or words, change case by rule, rearrange a sentence. Character-by-character reasoning is the skill, and it transfers directly from the arrays unit.
