I made a char[] with split and am trying to make it into a String again, but I don't know why this is not working

Question

Why will this code not print out a string?

String s = "My name is Jack";
    String[] arr = s.split("");
    char[] a = Arrays.toString(arr).toCharArray();
System.out.println(a);
System.out.println(new String(a));

Answer 1

You didn't make a char[] array, but rather a String[] array. Use String#toCharArray() instead:

String s = "My name is Jack";
char[] letters = s.toCharArray();
System.out.println(Arrays.toString(letters));
System.out.println(new String(letters));

Demo

Answer 2

It does print out a String, at least on the second println (the first println yields exactly the same output, but it does it without constructing the String).

Ideone demo

However, the chars of the string you are printing is obtained via:

char[] a = Arrays.toString(arr).toCharArray();

Arrays.toString gives you a string surrounded by [], separated with commas. So "hello" would look like:

[h, e, l, l, o]

You then get the chars of this string, and try to reconstitute it into a string (which is redundant anyway, just print Arrays.toString(arr)).

To print the joined string, use String.join:

String.join("", arr)