Why do I need istGroesser?

So if the input (quickly not a full 20 words) was ""Delta pilot from Berlin is learning Java bit by bit", the correct output would be: Berlin Delta Java bit bit by from is learning pilot

Yeah that worked, thanks! But in my opinion, when the task is asking for sort alphabetically, I want it to appear like this: Berlin bit bit by Delta from is Java learning pilot I think the task should be more clear in that way.

Alphabetically in programming means a different thing than alphabetically in the real world. This is a result of the underlying mechanism of computers being only able to process 2 values, 1 and 0, and how every characater in programming corresponding to a number denoted by these 1's and 0's. You can look at the ASCII table for the order that Strings are sorted. In between the Uppercase letters and lowercase letters there are these 6 characters: [ \ ] ^ _ `. This means that if you were to enter words such as: The world [is `has gone Insane _But was It ever ^sane to begin \with? the resulting sort would be: Insane It The [is \with? ^sane _But `has begin ever gone to was world This is not a codegym, or even Java, specific decision. These decisions were made by engineers in labs back when modern computers were first being invented. There are a lot of things in programming that don't mean the same thing in the real world, and unfortunately I won't be able to give you a list of these faux pas. Another one that I know of is how to set decimal numbers:

double test = 1.34e4;

If you were a mathematician or engineer, you would look at that and see the 'e' and there and expect it to be a logarithmic number, but in computer programming that means "times ten to the Nth power" as in "1.34 time ten to the 4th power". Its a strange one because computers were originally programmed by mathematicians and engineers, so using 'e' should mean been in its logarithm meaning, but its not.

Once again, thanks a lot, very good explanation! That´s very interesting and deserves its own topic under "links by the professor" ;)

Here is some example code:

public class Solution {
    public static void main(String[] args) throws Exception {
        int[] array = new int[3]; // create 1 object
        array[0] = 1; array[1] = 2; array[2] = 3; // fill its values
        int[] array1 = array; // new variable references same object
        int[] array2 = array1;// new variable references same object
        int[] array3 = array2;// new variable references same object
        print(array2); // outputs array2
        array3[1] = 5154; // changes array3's index 1 to 5154
        print(array); // prints array, notice it contains 5154
        array[0] = 4351; // changes array's index 0 to 4351
        print(array1); // outputs array1
        // notice it contains both 5154 and 4351
    }

    public static void print(int[] array) {
        System.out.println("Printing Array:");
        System.out.print("\t");
        for(int x : array){
            System.out.print(x + " ");
        }
        System.out.println();
    }
}
/* Outputs:
Printing Array:
	1 2 3
Printing Array:
	1 5154 3
Printing Array:
	4351 5154 3
*/

Thanks for this wonderful explanation! This concept was not completely clear to me from the lessons, but I think I figured it out now: So this only works for objects right? So for primitiv types like int, boolean etc. this won´t work? But when calling a Wrapper class like

Integer number = new Integer("123");

that would be the same case as for the array in your example.

I had the same exact question too when I first started understanding this concept =D Wrapper classes don't have setters to modify the internal data contained within, so when you change the data you are effectively creating a brand new object. This means that if you were to do this:

Integer number = new Integer("123");
Integer number2 = number; // number and number2 reference the same object
number = 124; // this creates a new Integer object that equals 124;

Where my last example, with the arrays, the data in all the variables always matched. If you were to output these two:

sout(number + " " + number2);

the output would be "124 123". (if you didn't know this already, typing sout in IntelliJ and hitting tab will auto-code in: System.out.println(); for you)

It is a bit confusing indeed, but I think I will get my head around it with some more practise! Yeah, I knew the one with sout ;) Hitting Enter after sout makes it too! But thanks for the tip, always appreciated!