Object-Oriented Programming Concepts

Object-Oriented Programming Concepts

• Class: Blueprint for an object, representing the concept of that object.
• Inheritance: Creating new classes from existing ones; the new class inherits variables and methods from the original class.
• Inheritance Relationships: Depicted with a solid arrow pointing to the parent class, representing an "is-a" relationship.
• Inheritance Benefits: Allows for software reuse, reducing development time and code size.
• Visibility Modifiers: Control the access level of variables and methods (public, protected, private).
• super Keyword: References the parent class, commonly used to invoke the parent's constructor.
• Overriding: Child class defines its own version of an inherited method.
• Overloading: Multiple methods with the same name but different signatures exist within the same class.
• final Keyword: Prevents methods from being overridden.

Class Hierarchy

• Siblings: Classes derived from the same parent class, sharing common characteristics but not inheritance between them.
• Common Features: Should be defined as high up in the class hierarchy as possible for efficiency and reusability.
• Transitive Inheritance: Inherited traits are passed down through multiple levels of inheritance.
• toString() Override: Customizes string representation of an object.
• equals() Method: Determines if two object references refer to the same object.

Interfaces

• Interface: Collection of abstract methods and constants, defining a set of methods that a class must implement.
• Abstract Method: Method header without a body; implementation is provided by the implementing class.
• Using Interfaces in Class Headers: Use the implements keyword to implement an interface.

Abstract Classes

• Abstract Class: Placeholder in a class hierarchy, representing a generic concept. Abstract classes cannot be instantiated.

Polymorphism

• Polymorphism: Ability to have multiple forms; a single interface can serve multiple implementations.
• Polymorphic Reference: Can refer to different object types at different times.
• Binding: Linking a method call to its corresponding definition at runtime.
• Dynamic Binding (Late Binding): Binding occurs at runtime, allowing for flexibility in method calls.
• Polymorphism via Interfaces: Same concepts apply to interfaces, where an interface reference can refer to any object implementing that interface.

Casting

• Casting: Converts an object reference to a specific type; used when the compiler needs explicit type information.

Sorting

• Sorting: Arranging items in a specific order.
• Selection Sort: Finds the smallest item in the unsorted portion of the list and swaps it with the first unsorted item.
• Insertion Sort: Inserts each item into its correct position in a sorted sublist.

Searching

• Search Pool: Group of items being searched.
• Searching: Finding a target element within a search pool.
• Linear Search: Examines each item in the pool sequentially.
• Binary Search: Requires a sorted array; repeatedly divides the search pool in half until the target is found.

Exceptions

• Exceptions: Represent problems or unusual situations that can occur during program execution.
• Error: Represents a serious, unrecoverable situation.
• Exception Handling: Using try-catch statements to identify and handle exceptions.
• try Block: Contains code that may throw an exception.
• catch Block: Defines the code to handle a specific exception type.
• finally Clause: Executed regardless of whether an exception is thrown or caught, often used for cleanup operations.
• Exception Propagation: When an exception is not caught, it propagates up the call stack until caught or until the program terminates.

Custom Exceptions

• Custom Exceptions: Defined by extending the Exception class.
• Throwable Class: Superclass of all errors and exceptions.
• throw Keyword: Starts exception propagation.
• Checked Exceptions: Must be caught or declared in the throws clause.
• Unchecked Exceptions: Not required to be caught or declared.

Explore the fundamental concepts of Object-Oriented Programming (OOP). This quiz will cover topics such as classes, inheritance, visibility modifiers, and method overriding. Test your understanding of how these concepts work together to create efficient and reusable code.