JAVA: storing input into array

Question

I need to write a program where the program would generate random letter and i would need to store this random character into an array

        char[] arrayRandom = new char[10];


        for (int i = 0; i < 8; i++) {
            randomNumLet = (generator.nextInt(20) + 1);
            System.out.print(arrayRandomLetter[randomNumLet] + " ");
            arrayRandomLetter[randomNumLet] = arrayRandom[i];
        }

is there anything wrong with my code? because when i run this and printed the array i get boxes for all the values in the array and there are some letter that this line of code cannot print

            System.out.print(arrayRandomLetter[randomNumLet] + " ");

Thanks

Answer 1

You're assigning an element of arrayRandomLetter a value from arrayRandom. As you never initialize arrayRandom, its values are all 0. 0 is not the value of a printable character, hence the boxes.

An easy way to pick a random character is like this:

String chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
char randomChar = chars.charAt(random.nextInt(chars.length()));

Answer 2

You are trying to print arrayRandomLetter before it is assigned.

Answer 3

I'm not going to give you the answer, but I will give you a hint:

(char)('A' + 1) is 'B'

@fastcodejava's answer explains why you are seeing "boxes" -- rendering the ASCII NUL character.

@Mark Peters is also correct, but that's not the simplest solution.