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Unit 7: Multidimensional Arrays

Objectives Notes

After studying this unit, you will be able to:
• Understand the concepts of multidimensional array
• Discuss how to extract the arrays
• Discuss how to perform conversion between arrays and variables
• Explain array traversal
• Understand the multidimensional array sorting
• Explain how to perform different operations on array
• Discuss the use of arrays

Introduction

A multidimensional array is an array that contains at least one other array as the value of one
of the indexes.

Arrays do not have to be a simple list of keys and values each location in the array can
hold another array. This way, we can create a two-dimensional array. You can think of a
two-dimensional array as a matrix, or grid, with width and height or rows and columns.
7.1 Concept of Multidimensional Array

Array does not have to be a simple list of keys and values; each array element can contain
another array as a value, which in turn can hold other arrays as well. In such a way you can
create two-dimensional or three-dimensional arrays.
• Two-dimensional Arrays
• Three-dimensional Arrays
7.1.1 Two-dimensional Arrays

Imagine that you are an owner of a flower shop. One-dimensional array is enough to keep titles
and prices. But if you need to keep more than one item of each type you need to use something
different. One of the ways to do it is using multidimensional arrays. The table below might
represent our two-dimensional array. Each row represents a type of flower and each column
– a certain attribute.
Table 7.1: Two-dimensional Arrays
Title Price Number
rose 1.25 15
daisy 0.75 25
orchid 1.15 7

To store data in the form of array represented by preceding example using PHP, let’s prepare
the following code:
Example:

<?php
$shop = array( array(“rose”, 1.25 , 15),
array(“daisy”, 0.75 , 25),
array(“orchid”, 1.15 , 7)
);
?>

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