Change this to As you can see in the JavaDoc, the method does not change the argument listItems, rather it returns a new array with the remaining elements. Edit You also need to change your deletion method to So you could return the new array with the remaining elements.
In Java, you cannot directly write the executable statements in class. You need to move your code in a method. Only variables declaration is allowed outside the method/blocks. Just for the sake of testing, ,move everthing to main method. Try this: Note: system.out.println(arrayList); will throw an error because there is no varaible called arrayList, i think it should … Read more
Since Date implements Comparable, it has a compareTo method just like String does. So your custom Comparator could look like this: The compare() method must return an int, so you couldn’t directly return a boolean like you were planning to anyway. Your sorting code would be just about like you wrote: A slightly shorter way to write all this, if you don’t need to reuse your comparator, is to … Read more
by default 12.3 is double literal, So to tell compiler to treat it as float explicitly -> it uses f or F
Enums are classes and should follow the conventions for classes. Instances of an enum are constants and should follow the conventions for constants. So There is no reason for writing FruitEnum any more than FruitClass. You are just wasting four (or five) characters that add no information. This approach is recommended by and used in … Read more
I need to know how to fix these error notes: Here is my code:
That’s pretty easy: Note that I didn’t either make the methods themselves synchronized or synchronize on this. I firmly believe that it’s a good idea to only acquire locks on objects which only your code has access to, unless you’re deliberately exposing the lock. It makes it a lot easier to reassure yourself that nothing … Read more
You need to follow a few steps to debug properly. 1) mvn clean dependency:tree Take a look at the output to see exactly what you get and verify your dependencies are all there. 2) mvn clean compile. Does this fail? If not does that mean you only get the error in Eclipse? You mentioned in … Read more
You can add a jar in Eclipse by right-clicking on the Project → Build Path → Configure Build Path. Under Libraries tab, click Add Jars or Add External JARs and give the Jar. A quick demo here. The above solution is obviously a “Quick” one. However, if you are working on a project where you need … Read more
You should remove the references to it by assigning null or leaving the block where it was declared. After that, it will be automatically deleted by the garbage collector (not immediately, but eventually). Example 1: Example 2: Not something that you are currently looking for, but FYI: you can invoke the garbage collector with the … Read more