Why does the toString method in java not seem to work for an array

To get a human-readable toString(), you must use Arrays.toString(), like this:

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

Java's toString() for an array is to print [, followed by a character representing the type of the array's elements (in your case C for char), followed by @ then the "identity hash code" of the array (think of it like you would a "memory address").

This sad state of affairs is generally considered as a "mistake" with java.

See this answer for a list of other "mistakes".

I don't know where you get the idea that "in principle" it should print "abcdef". Where is that documented?

Something like [C@6e1408 is certainly not random gibberish - it's the same way of constructing a string from an object as any other type that doesn't override toString() inherits - it's a representation of the type ([ indicating an array; C indicating the char primitive type) followed by the identity hash code in hex. See the documentation for Object.toString() for details. As it happens, arrays don't override toString.

If you want [a, b, c, d, e, f] you can use Arrays.toString(char[]). If you want abcdef you can use new String(char[]).

Arrays don't override toString. There's a static method: java.util.Arrays.toString that should solve your problem.

import java.util.Arrays;
class toString {
    public static void main(String[] args){
        char[] Array = {'a', 'b', 'c', 'd', 'e', 'f'};
        System.out.println(Arrays.toString(Array));
    }
}