java core

Java divides exceptions into two main categories: checked and unchecked exceptions. Understanding the distinction is crucial for effective exception handling and robust application design. Feature Checked Exceptions Unchecked Exceptions Compile-Time Checking Yes – compiler enforces handling No – compiler does not require handling Inheritance Subclasses of Exception (but not RuntimeException) Subclasses of RuntimeException Handling Requirement […]

In Java, custom exceptions are user-defined exceptions that extend the built-in Exception or RuntimeException classes. They allow you to represent specific error conditions that are meaningful to your application domain, improving code clarity, maintainability, and robustness. Why Create Custom Exceptions? Domain-Specific Clarity: Standard exceptions like IOException or NullPointerException may not describe application-specific issues precisely. Custom

The throw statement in Java is used to explicitly throw an exception in your code. When you throw an exception, the normal flow of the program is interrupted, and control is transferred to the nearest catch block that can handle the type of exception thrown. If no suitable catch block is found, the program terminates.

In Java, throwing exceptions is an essential part of error handling, allowing you to signal that something unexpected has occurred during the execution of your program. This mechanism is used to indicate abnormal behavior and to provide control over how the program reacts to various error conditions. Key Points About Throwing Exceptions: throw keyword: The

Rethrowing exceptions in Java allows you to catch an exception and throw it again, either in the same or a modified form. This is a useful technique when you want to log or handle an exception partially, but you still want the exception to propagate up the call stack for higher-level handling. Key Points: Partial

In Java, catching multiple exceptions allows you to handle different types of exceptions in a more concise and efficient way, especially when the handling logic for those exceptions is the same. Prior to Java 7, you would need to write separate catch blocks for each exception type. But with Java 7 and onwards, you can

In Java, the finally block is used to execute important code such as resource cleanup, regardless of whether an exception is thrown or not. It is associated with try-catch blocks and is always executed after the try and catch blocks, even if an exception is thrown or if there is no exception. Key Features: Guaranteed

In Java, nested try-catch blocks refer to placing one try-catch block inside another. This structure allows you to handle exceptions at multiple levels of granularity, making your code more resilient and easier to debug in complex situations. Purpose and Use-Cases Nested try-catch blocks are useful when: You need to handle different types of exceptions in

In Java, a try block can be followed by multiple catch blocks, allowing you to handle different types of exceptions separately. This structure helps make your exception handling more robust and fine-grained. Syntax Important Rules Order matters: Always catch the more specific exceptions before the more general ones. If you catch a superclass (like Exception)

The try-catch block in Java is used to handle exceptions at runtime. It allows developers to write code that might throw an exception (try block), and then catch and handle specific types of exceptions (catch block), preventing abrupt termination of the program. Basic Syntax From above, try block: Contains the code that may potentially throw