Random Array Generator Java

Question

I need to initialize an array of characters with 1000 random characters between [a,..z] and [A,..,Z].

I don’t want do this by first generating only characters between [a,..z] and then only characters in [A...Z] but treat all 52 characters equally.

I know one way to do this is to generate a random number between 0 and 51 and assign it one of the character values.

How would I approach this problem or assign values to the random numbers between 0 and 51?

Answer 1

You have got the interesting code idea. Here might be the thought.

1. Take all the a-z and A-Z and store them in an array[].
2. Randomly generate a number between 1-52 (use API classes for that).
3. You will get a number in step 2, take it as an array index and pick this index from array[] of chars.
4. Place that picked char to your desired location/format............
5. Process it.

Best Regards.

Answer 2

Let me give you some general guidelines. The "one way to do this" you mentioned works. I recommend using a HashMap<E>. You can read more about hashmaps in the docs:

http://docs.oracle.com/javase/7/docs/api/java/util/HashMap.html

Alternatively, you can use another array that contains a - z and A - Z and you can use the index number to refer to them. But in this case I think it makes more sense to use a HashMap<E>.

I think you know how to create a Random object. But if you don't, check out the docs:

http://docs.oracle.com/javase/7/docs/api/java/util/Random.html

So you basically use the nextInt method of the Random class to generate a random number. And you can put that random number into your HashMap or array. And then you just put that character you get into an array that stores the result of the program.