Question

Java code about writing two methods:

public static String randomStringone(int length)

public static String randomStringtwo(int length)

This method should return a String of random lowercase letters with the given length by using for loops. To generate a random lowercase letter, use a local Random variable and the method nextInt() to generate a number between 97 and 122, then cast the result to a char. The method nextInt() can be found here: https://www.geeksforgeeks.org/java-util-random-nextint-java/   

• In randomStringone(), you should use String concatenation like exampleString = exampleString + exampleChar;
• In randomStringtwo(), use the methods provided by the StringBuilder class to build your String. You will create an instance of a StringBuilder and use it to manipulate the string in progress. You need to:
  • Append chars to a StringBuilder
  • Get the String from the StringBuilder (information about StringBuilder: https://docs.oracle.com/javase/10/docs/api/java/lang/StringBuilder.html)

Answer 1

import java.util.Random;

public class RandomStrings {

    public static String randomStringone(int length) {
        Random random = new Random();
        String s = "";
        for (int i = 0; i < length; i++) {
            s += (char) (97 + random.nextInt(26));
        }
        return s;
    }

    public static String randomStringtwo(int length) {
        Random random = new Random();
        StringBuilder s = new StringBuilder();
        for (int i = 0; i < length; i++) {
            s.append((char) (97 + random.nextInt(26)));
        }
        return s.toString();
    }

    public static void main(String[] args) {
        // testing code. Remove it if not required..
        System.out.println(randomStringone(10));
        System.out.println(randomStringtwo(15));
    }

}