final vs finally vs finalize in Java

Three similar-looking words

final, finally and finalize look alike but are completely unrelated. final is a keyword, finally is a block, and finalize is a method. This is a favourite interview question, so it helps to know each one clearly.

final — the keyword

final int MAX = 100;
// MAX = 200;   // ERROR: cannot change a final variable

final class Utility { }        // cannot be extended
// final method cannot be overridden

final prevents change. A final variable cannot be reassigned, a final method cannot be overridden, and a final class cannot be extended. It is about making things constant or fixed.

finally — the block

try {
    int x = 5 / 0;
} catch (ArithmeticException e) {
    System.out.println("Caught error");
} finally {
    System.out.println("Always runs");
}

The finally block runs after try-catch no matter what — whether an exception happened or not, and even if there is a return. It is used for cleanup like closing files.

finalize — the method

// finalize() was called before garbage collection
// protected void finalize() { ... }
// DEPRECATED — do not use in modern Java

finalize() was a method the garbage collector called before destroying an object, meant for last-minute cleanup. It was unreliable and is now deprecated. Modern code uses try-with-resources instead.

Side-by-side

What you actually use

• final — used often, for constants and to lock down classes/methods.
• finally — used for cleanup, though try-with-resources often replaces it.
• finalize — do not use; it is deprecated.

So in real code you use final and finally regularly, and avoid finalize entirely.

Common mistakes

• Thinking they are related. They share letters, not purpose.
• Reassigning a final variable. That causes a compile error.
• Expecting finally to be skipped. It runs even after a return in try.
• Using finalize. It is deprecated — use try-with-resources.

Summary

• final is a keyword that prevents change (variable, method, class).
• finally is a block that always runs after try-catch.
• finalize was a pre-garbage-collection method, now deprecated.
• Use final and finally regularly; avoid finalize.
• They only look similar — their jobs are unrelated.

Next, handle errors with custom exceptions, or learn cleanup of memory in garbage collection.