Thread: String Builder questions

When I say:

StringBuilder strBuilder = new StringBuilder();
       for(char alph = 'a'; alph <= 'z'; alph++)
            {
                strBuilder.append(alph);
                System.out.println(strBuilder);
            }

output:
"a
ab
abc
abcd..."

What I want to do now is generate a Char[][] based on user input for the dimensions. Then I will randomly generate characters from the alphabet to fill the array. Should I use the StringBuilder class for this? Or is there a simple way to generate random letters with math.Random?

That is I know how to generate a random letter between a-z:

Random r = new Random();
      char c = (char)(r.nextInt(26) + 'a');

However; i'm not sure how to store those values into a Char[][]. So I figured maybe I could do it with StringBuilder.

generate random letters with math.Random

char are numeric values in the range: 'a' to 'z' and 'A' to 'Z'
To see the value use an (int) cast: System.out.println((int)'a');
The Math.random() method can be used in an expression to generate int values in the range: 'a' to 'z' which can be cast to char.

Or the chars could be put into an array and a random index used to select the elements of the array.