COMP SCI MIDTERM

Here are definitions of the terms as they relate to Java:

Chapter 1:

Hardware, Program, and Software

• Hardware: The physical components of a computer, such as the CPU, memory, and storage.

• Program: A set of instructions that a computer follows to perform a task.

• Software: The collection of programs that control hardware and execute tasks.

Programming Language, JAVA Programming Language

• Programming Language: A formal set of instructions that a computer can execute.

• JAVA Programming Language: A high-level, object-oriented language that is platform-independent due to the Java Virtual Machine (JVM).

Identifiers, Legal Identifiers

• Identifiers: Names used for variables, methods, classes, etc.

• Legal Identifiers: Must start with a letter, underscore, or dollar sign and cannot be a Java keyword.

White Space

• Spaces, tabs, and newlines that improve readability but do not affect execution.

Program Development

• The process of designing, writing, testing, and maintaining a program.

Language Levels

• Levels of programming abstraction: Machine language, Assembly, High-level language (e.g., Java).

Compilation

• Converting Java source code into bytecode using the Java compiler.

Java Translation

• The process where Java source code is compiled into bytecode and then interpreted by the JVM.

Development Environments

• Tools used for Java programming (e.g., Eclipse, IntelliJ, NetBeans).

Syntax and Semantics

• Syntax: The rules governing the structure of valid Java code.

• Semantics: The meaning of Java statements.

Three Types of Errors

1. Syntax Errors: Violations of Java's rules (e.g., missing semicolons).

2. Runtime Errors: Errors occurring during execution (e.g., division by zero).

3. Logical Errors: Incorrect logic leading to undesired output.

Problem Solving

• The process of designing a solution and implementing it in code.

Development Activities

• Steps in creating a program: analysis, design, coding, testing, debugging.

Object-Oriented Programming (OOP)

• A programming paradigm based on objects and classes.

Objects

• Instances of a class containing attributes (fields) and behaviors (methods).

Classes

• Blueprints for creating objects.

Classes and Objects

• Classes define object properties; objects are instances of classes.

Chapter 2:

Character Strings

• Sequences of characters handled by the String class.

Two Ways to Create String Objects

1. Using string literals: String s = "Hello";

2. Using new: String s = new String("Hello");

Println/print Method

• System.out.print(): Prints without a newline.

• System.out.println(): Prints with a newline.

String Concatenation

• Combining strings using +: "Hello" + " World" results in "Hello World".

Escape Sequences

• Special characters (\n, \t, \\, etc.).

Variables

• Named storage locations in memory.

Assignment

• Assigning values using =.

Constants

• Immutable values declared with final.

Primitive Data Types

• byte, short, int, long, float, double, char, boolean.

Numeric Types

• Integer (int, long) and floating-point (float, double).

Characters

• Represented using char, e.g., char c = 'A';.

Booleans

• true or false values.

Expressions

• Combinations of variables, operators, and values.

Division and Remainder

• / for division, % for remainder.

Assignment Revisited

• Assigning values with operators (+=, -=, etc.).

Increment and Decrement Operators

• ++ and -- increase or decrease a variable by 1.

Assignment Operators

• =, +=, -=, *=, /=, %=.

Data Conversions

1. Assignment Conversion: Implicit conversion in assignments.

2. Promotion: Widening conversion (e.g., int to double).

3. Casting: Explicit conversion using (type).

Scanner Class

• Used for input reading (Scanner sc = new Scanner(System.in);).

Reading Input

• Methods like nextInt(), nextDouble(), nextLine().

Input Tokens

• Individual units of input parsed by Scanner.

Chapter 3:

Creating Objects

• ClassName obj = new ClassName();

Creating Strings (Two Ways)

1. Using literals.

2. Using new.

Invoking Methods

• Calling methods on objects: obj.method();.

Object References

• Variables storing memory addresses of objects.

Assignment Revisited

• Assigning references, not copying objects.

Aliases

• Multiple references to the same object.

String Class and Methods

• Methods like length(), substring(), toUpperCase().

Java API/Packages

• Predefined Java libraries.

Import Declarations

• import java.util.Scanner;.

The java.lang Package

• Implicitly imported (contains Math, String, etc.).

Random Class

• Generates random numbers (Random rand = new Random();).

Wrapper Classes

• Convert primitives to objects (Integer, Double, etc.).

Autoboxing

• Automatic conversion between primitives and wrapper objects.

Chapter 7:

Definition of Array

• A collection of elements of the same type.

Declaring Arrays

• int[] arr;.

Using Arrays

• Access elements with indices.

Bounds Checking

• Java prevents accessing indices out of range.

Alternate Array Syntax

• int arr[];.

Initializer Lists

• int[] arr = {1, 2, 3};.

Two-Dimensional Arrays

• int[][] matrix = new int[3][3];.

Pros and Cons of Arrays

• Pros: Fast access, easy iteration.

• Cons: Fixed size, memory overhead.

Chapter 8:

Concepts of Inheritance

• A subclass inherits attributes and methods from a superclass.

Examples of Parent/Child Classes

• Words: Noun extends Word.

• Book: Ebook extends Book.

• Hospital Employee: Doctor extends Employee.

The protected Modifier

• Allows subclass access but prevents outside access.

The super Reference

• Calls superclass constructor/methods.

Overloading vs. Overriding

• Overloading: Same method name, different parameters.

• Overriding: Redefining superclass methods in a subclass.

Class Hierarchies

• Organized structure of classes.

The Object Class

• The root of all Java classes.

Abstract Classes

• Cannot be instantiated; contains abstract methods.

Visibility Revisited

• public, private, protected.

Designing for Inheritance

• Using super and protected members.

Chapter 9:

Binding

• The association of a method call with its definition.

What is Polymorphism?

• The ability of a method to take different forms.

References and Inheritance

• A superclass reference can hold a subclass object.

Polymorphism via Inheritance

• Subclasses can override superclass methods and be referenced polymorphically.

Let me know if you need further clarification on any term!