Boost Java Readability with Unnamed Patterns and Variables in Java 21

Java 21 introduces a preview feature called Unnamed Patterns and Variables (in addition to JEP 445) aimed at improving code readability and maintainability.

Traditionally a try‑catch block is written as:

try {
    // ...
} catch (Exception e) {
    System.out.println("An error has occurred!");
}

Here the variable e is often unused.

With the new JEP 443 feature you can replace the unused variable with an underscore:

try {
    // ...
} catch (Exception _) {
    System.out.println("An error has occurred!");
}

In short, any declared variable that you do not intend to use can be replaced by the underscore _, which applies to try‑catch blocks, for‑loops and other scenarios.

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