How many types of exceptions are there in java with examples
How many types of exceptions are there in java with examples
I'll respond in English since you specifically asked for it.
Java has several types of exceptions that can be thrown during the execution of a program. Here's an overview of the most common types:
1. Checked Exceptions
Checked exceptions are those that must be explicitly handled by the programmer using try-catch blocks or by declaring them in the method signature using throws. Examples include:
Example: public void readFile(String file) throws IOException { ... }
2. Unchecked Exceptions
Unchecked exceptions, also known as runtime exceptions, are those that can be thrown at any time during the execution of a program and are not required to be handled explicitly by the programmer. Examples include:
NullPointerException (when trying to access an object's field or method without checking for null) ArrayIndexOutOfBoundsException (when accessing an array element beyond its bounds)Example: String name = null; System.out.println(name.length()); // throws NPE
3. Error Exceptions
Error exceptions are a type of unchecked exception that indicates a severe problem, such as:
OutOfMemoryError (when the JVM runs out of memory)
Example: try { String str = new String(new byte[Integer.MAX_VALUE]); } catch (OutOfMemoryError e) {}
4. Runtime Exceptions
Runtime exceptions are a type of unchecked exception that can occur during the execution of a program, such as:
Example: int x = 5 / 0; // throws ArithmeticException
5. Logic Exceptions
Logic exceptions are not officially recognized by the Java Language Specification but can be considered as a type of unchecked exception that occurs due to logical errors or inconsistencies in the program, such as:
IllegalStateException (when an operation is performed on an object in an invalid state) ConcurrentModificationException (when multiple threads concurrently modify the same data structure)Example: List<String> list = new ArrayList<>(); list.add(null); // throws NPE when accessing
These are just a few examples of the many types of exceptions that can be thrown in Java. Understanding how to handle and throw exceptions is crucial for writing robust and reliable programs.
(Note: I'll make sure to keep my responses concise and not exceed 300 words.)
How many types of checked exceptions are there in Java?
I'm happy to respond in English for you!
In Java, a checked exception is an error that the compiler checks and forces you to handle at runtime using try-catch blocks or methods that declare them as part of their method signature. There are two types of checked exceptions: Exception and its subclasses.
The top-level class Exception is the superclass of all checked exceptions in Java. It represents the base type for all checked exceptions.
NullPointerException, ArrayIndexOutOfBoundsException, and ClassCastException. Since they are unchecked, you don't need to declare them in your method signature. However, when an exception of this type is thrown from within a try block, it will propagate through any subsequent catch blocks until it reaches the topmost level of the program.
Examples: ArithmeticException, ArrayIndexOutOfBoundsException, ClassCastException, IllegalStateException, and NullPointerException.
OutOfMemoryError, StackOverflowError, and LinkageError. Like runtime exceptions, you don't need to declare them in your method signature, but they will still propagate through any subsequent catch blocks until they reach the topmost level.
Examples: AbstractMethodError, AssertionError, linkingError, OutOfMemoryError, and StackOverflowError.
It's essential to understand that not all exceptions are checked. Unchecked exceptions are subclasses of RuntimeException or Error. Java requires you to handle checked exceptions using try-catch blocks, whereas unchecked exceptions can propagate through your program without explicit handling.
In summary, there is only one top-level class Exception, and its direct subclasses are RuntimeException (representing runtime exceptions) and Error (representing errors). This distinction helps ensure that your Java programs are robust, reliable, and maintainable.
