Multi-Dimensional Arrays

The arrays you have been using so far have only held one column of data. But you can set up an array to hold more than one column. These are called multi-dimensional arrays. As an example, think of a spreadsheet with rows and columns. If you have 6 rows and 5 columns then your spreadsheet can hold 30 numbers. It might look like this:

A multi dimensional array is one that can hold all the values above. You set them up like this:

int[ ][ ] aryNumbers = new int[6][5];

Arrays

Java Arrays

A programming concept you just have to get used to if you're to code effectively is the array. In this section, you'll learn what arrays are, and how to use them.

What is an Array?

So far, you have been working with variables that hold only one value. The integer variables you have set up have held only one number, and the string variables just one long string of text. An array is a way to hold more than one value at a time. It's like a list of items. Think of an array as the columns in a spreadsheet. You can have a spreadsheet with only one column, or lots of columns. The data held in a single-list array might look like this:

Like a spreadsheet, arrays have a position number for each row. The positions in an array start at 0 and go up sequentially. Each position in the array can then hold a value. In the image above array position 0 is holding a value of 10, array position 1 is holding a value of 14, position 2 has a value of 36, and so on.
To set up an array of number like that in the image above, you have to tell Java what kind of data is going in to your array (integers, strings, boolean values, etc). You then need to say how many positions the array has.

Java Code Snippets

Short but useful pieces of Java code. Click on the link below.

Java Code Snippets