[TheBlueSuede]

I'm currently doing some online classes to learn Java. I feel like the book I'm reading has a ton of examples without enough explanations. Right now I'm trying to understand arrays and multidimensional arrays. Right now there's a discussions that came up in the class. It assumes the following:

PHP Code


<?php 
int[][][] x = new int[12][5][2] 


How many elements are in the array?
What is x.length?
What is x[2].length?
What is x[0][0].length?


Now, I know there are 120 elements in the array because 12 5 2 = 120.
However, I'm not understanding why the .length gives me the following numbers: 12, 5, 2.
I feel like I could have guessed the answers and got it correctly. But guessing doesn't quite help me understand arrays. In order for me to get the answers, I just created a class in eclipse to print the length.

Can someone provide some more insight into multi-dimensional arrays?

PHP Code


<?php 
public class multidim {

    public static void main(String[] args) {
        
        int[][][] x = new int[12][5][2];

        System.out.println(x.length);
        System.out.println(x[2].length);
        System.out.println(x[0][0].length);

    }

} 


[k45h]

You are simply accessing the length of each different dimension in your 3d array.

1d Array = 1 row, several columns
2d Array = several rows, several columns. So picture a 2d table
3d Array = several 2d tables (picture them in-line behind one another)

Keep in mind you have initialised the 3d array so that each row is the same length, in Java the rows can all be different lengths.

---

I'd check the 3d array section of this article, might explain it better but you need to see it visually and it might help you to understand.

https //www geeksforgeeks org/multidimensional-arrays-in-java/

[TheBlueSuede]

You are simply accessing the length of each different dimension in your 3d array.

1d Array = 1 row, several columns
2d Array = several rows, several columns. So picture a 2d table
3d Array = several 2d tables (picture them in-line behind one another)

Keep in mind you have initialised the 3d array so that each row is the same length, in Java the rows can all be different lengths.

---

I'd check the 3d array section of this article, might explain it better but you need to see it visually and it might help you to understand.

https //www geeksforgeeks org/multidimensional-arrays-in-java/

This is perfect. THank you!

[lockhead]

When you try to conceptualize multidimensional arrays it's quite useful to think of them like you would a coordinate system.
1D: Just a line of numbers like a list, 1 row, multiple columns.
2D: Think of a chess board or a coordinate system: multiple rows, multiple columns which can be addressed with (x/y) coordinates
3D: Like a 3d coordinate system (a cube for example) which can address with (x/y/z) coordinates