Printing the alphabet using for loop. Why must I explicitly convert character [] to string?

Question

I am trying to print the letters of the alphabet in caps. So I wrote this in a for loop:

System.out.print(Character.toChars(i));
//where i starts at 65 and ends at 90

This works fine and prints the letters but In my code I wanted to put a space between the letters to make it look nicer. So i did this:

System.out.print(Character.toChars(i) + " ")

Why does it print the memory address of the characters instead of the letter? The solution I came up with was to explicitly convert the char to a new String object:

String character = new String(Character.toChars(i));
        System.out.print (character + " ");

but I'm not quite sure why I can't just write "Character.toChars(i)"

In the first one Does the method(Character.toChars()) point to the address of the character and System.out.print is smart enough to print the value at that address? i.e the corresponding letter?

Answer 1

System.out.print(Character.toChars(i)) calls PrintStream.print(char[]), an overload that handles char[] specially.

Character.toChars(i) + " " is really equivalent to Character.toChars(i).toString() + " "; calling toString() on an array type results in a string representation of its address (this behaviour is directly inherited from Object).

A simpler solution for your particular case may be this:

System.out.println((char)i + " ");

Answer 2

The Character.toChars method returns char[], which will be represented as [C@<hex hashcode> in String form.

You don't need to use the toChars method (or do any casting at all):

for (char c = 'A'; c <= 'Z'; c++) {
    System.out.print(c + " ");
}

Answer 3

You use string concatenation, with one side being an array of chars and the other a string and according to the Java language specification, then as the char array is not a primitive type, but a reference value (aka an object), its toString method is called. And as there is no specific method implemented for arrays, they inherit the method implementation from java.lang.Object, which prints the address.

On the other hand, System.out.print(Character.toChars(i)) calls a specific implementation of print for character arrays, see the documentation of PrintStream.