Lowercase to Uppercase, Length of Array, Character count

import java.util.Arrays;

public class Main{

     public static void main(String []args){

        char c1='s';

        String str1="rock";

        char[] str2= {'s', 't', 'a', 'r'};

        String str3=new String("star");

        String str4="star";

        System.out.println(str1+" "+str3);

        System.out.println(str1.toUpperCase()+ " "+str3.toUpperCase());

        System.out.println(Arrays.toString(str2));

        int arrLength = str2.length;

        System.out.println("The length of array is: " + arrLength);

        

        System.out.println(str1+ str1.length());

        System.out.println(str2.length);

     }

}

Output: 

rock star                                                                                                               

ROCK STAR                                                                                                               

[s, t, a, r]                                                                                                            

The length of array is: 4                                                                                               

rock4                                                                                                                   

4