Which Return Statement Reigns Supreme: Unraveling the Definitive Value in a Try-Finally Block?

The Conundrum of Multiple Returns: Unraveling the Definitive Return Value

Imagine a scenario where a method's execution traverses multiple return statements within a try-finally block. A natural question arises: Which return statement ultimately determines the method's final return value? To delve into this enigma, let's analyze a specific code snippet:

String test() {
    try {
        return "1";
    } finally {
        return "2";
    }
}

The intrigue lies in understanding whether the return value from a call to test() is consistent across all Java Virtual Machines (JVMs). The Java Language Specification holds the key to this mystery.

Uncovering the Language Specifications' Stance

According to the Java Language Specification, the return from the finally block overwrites the return from the try block. Thus, "2" is unequivocally designated as the final return value, regardless of the JVM being employed.

Confirming Conformance with Sun JVM and Beyond

Empirically, the Sun JVM adheres to this specification, consistently rendering "2" as the return value for test(). However, it is crucial to note that this conformance is not merely a JVM-specific quirk.

The specification explicitly mandates it, and any JVM that deviates from it is deemed non-compliant. Therefore, it is safe to assert that the definitive return value will always be "2" in any spec-abiding JVM.

A Sober Warning: Avoid Coding Abominations

While the specification provides clarity on the return value behavior, it is strongly advised against employing multiple returns within a single method. Such coding practices introduce unnecessary confusion and violate fundamental coding principles.

Compilers will often issue warnings against this questionable approach, as exemplified by Eclipse's assertion that the return block of test() will never execute (erroneously). Embrace the wisdom of the language spec and avoid these coding abominations.

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