printing_the_contents_of_an_array.md

Printing the Contents of an Array

If you try to use System.out.println to output a String[] you won't see the contents of the array. Instead you will see something like [Ljava.lang.String;@1c655221.

~void main() {
String[] shout = { "fus", "ro", "dah" };
// [Ljava.lang.String;@5a07e868
System.out.println(shout);
~}

A similar thing will happen with int[], boolean[], and double[].¹

~void main() {
int[] nums = { 11, 11, 11 };
// [I@5a07e868
System.out.println(nums);

boolean[] bools = { true, false };
// [Z@5a07e868
System.out.println(bools);

double[] doubles = { 1.1, 1.1, 1.1 };
// [D@5a07e868
System.out.println(bools);
~}

The only kind of array which will include its contents when printed is a char[]. It will be printed as if it were a String.

~void main() {
char[] continent = { 'T', 'a', 'm', 'r', 'i', 'e', 'l' };
// Tamriel
System.out.println(continent);
~}

If you want to actually see the contents of an array, you should use a loop.²

~void main() {
String[] factions = { "empire", "stormcloaks", "dragons" };

int index = 0;
while (index < factions.length) {
    System.out.println(factions[index]);
    index++;
}
~}

Footnotes

1. What [I@5a07e868 and co. mean isn't really important. Try not to get too distracted by it. ↩

2. Later on, there will be easier ways to do this sort of inspection. This is just the one I can demonstrate now. ↩