When an exception is thrown within the body of a try statement, the catch clauses of the try statement are examined in the order in which they appear. The first catch clause that is capable of handling the exception is executed. The remaining catch clauses are ignored.
In Java, when an exception is thrown within a try block, the Java runtime system looks for the appropriate catch clause to handle that exception. The process is based on the type of exception that was thrown. The catch clauses are evaluated in the order they appear, and the first catch clause that matches the type of the thrown exception (or a type compatible with it) is executed.
The order of catch clauses is significant because if a more general exception type is placed before a more specific one, the more specific catch block will be unreachable and result in a compilation error.
Here’s a simple example:
try {
// Some code that may throw an exception
// ...
} catch (IOException e) {
// Handle IOException
} catch (Exception e) {
// Handle more general exceptions
}
In this example, if an IOException is thrown, the first catch block will be executed. If a different exception, say a NullPointerException, is thrown, the second catch block will handle it. If the catch blocks were reversed, the IOException block would be unreachable, and it would result in a compilation error.
It’s important to catch exceptions in a way that handles more specific exceptions first and then more general ones to avoid unreachable code and ensure proper exception handling.