What are good reasons to prohibit inheritance in Java, for example by using final classes or classes using a single, private parameterless constructor? What are good reasons of making a method final? 11 Answers 11
In Java, it is perfectly legal to define final arguments in interface methods and do not obey that in the implementing class, e.g.: public interface Foo { public void foo(int bar, final int baz); } public class FooImpl implements Foo { @Override public void foo(final int bar, int baz) { … } } In the … Read more
I have a simple question about strings in Java. The following segment of simple code just concatenates two strings and then compares them with ==. String str1=”str”; String str2=”ing”; String concat=str1+str2; System.out.println(concat==”string”); The comparison expression concat==”string” returns false as obvious (I understand the difference between equals() and ==). When these two strings are declared final … Read more
Edited: I need to change the values of several variables as they run several times thorugh a timer. I need to keep updating the values with every iteration through the timer. I cannot set the values to final as that will prevent me from updating the values however I am getting the error I describe … Read more
In Java, static final variables are constants and the convention is that they should be in upper-case. However, I have seen that most people declare loggers in lower-case which comes up as a violation in PMD. e.g: private static final Logger logger = Logger.getLogger(MyClass.class); Just search googleor SO for “static final logger” and you will … Read more
In Java, what’s the difference between: private final static int NUMBER = 10; and private final int NUMBER = 10; Both are private and final, the difference is the static attribute. What’s better? And why? 22 Answers 22
I’m playing with lambdas in Java 8 and I came across warning local variables referenced from a lambda expression must be final or effectively final. I know that when I use variables inside anonymous class they must be final in outer class, but still – what is the difference between final and effectively final? 14 … Read more
What is the difference between const and final keyword in Dart? 15 Answers 15
In Java we see lots of places where the final keyword can be used but its use is uncommon. For example: String str = “abc”; System.out.println(str); In the above case, str can be final but this is commonly left off. When a method is never going to be overridden we can use final keyword. Similarly … Read more
I can’t understand where the final keyword is really handy when it is used on method parameters. If we exclude the usage of anonymous classes, readability and intent declaration then it seems almost worthless to me. Enforcing that some data remains constant is not as strong as it seems. If the parameter is a primitive … Read more
