Question

Write in Java and explain all the code.
Have a unit test implemented in the main method.
Show example of the execution
Write a filter to clean a text, which is to say to delete all the characters that are not alphabetic, plans or a newline. And besides deleting them they should all also be replaced with a blank spot, so that the number of characters are still the same as the text before it was cleaned.

Answer 1

If you have any doubts, please give me comment...

public class FilterText{

    public static void main(String[] args) {

        String result = filter("Hi! th#s is test!ng!");

        System.out.println(result);

    }

    public static String filter(String str){

        String result = "";

        for(int i=0; i<str.length(); i++){

            if(Character.isAlphabetic(str.charAt(i)))

                result += str.charAt(i);

            else

                result += " ";

        }

        return result;

    }

}