For example, consider the following string:
CHAPTER 3 ?– PHP BASICS 67
$color = "maroon";
You could retrieve a particular character of the string by treating the string as an
array, like this:
$parser = $color[2]; // Assigns 'r' to $parser
Compound Datatypes
Compound datatypes allow for multiple items of the same type to be aggregated
under a single representative entity. The array and the object fall into this category.
Array
It??™s often useful to aggregate a series of similar items together, arranging and referencing
them in some specific way. This data structure, known as an array, is formally
defined as an indexed collection of data values. Each member of the array index (also
known as the key) references a corresponding value and can be a simple numerical
reference to the value??™s position in the series, or it could have some direct correlation
to the value. For example, if you were interested in creating a list of U.S. states, you could
use a numerically indexed array, like so:
$state[0] = "Alabama";
$state[1] = "Alaska";
$state[2] = "Arizona";
...
$state[49] = "Wyoming";
But what if the project required correlating U.S. states to their capitals? Rather
than base the keys on a numerical index, you might instead use an associative index,
like this:
$state["Alabama"] = "Montgomery";
$state["Alaska"] = "Juneau";
$state["Arizona"] = "Phoenix";
.
Pages:
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152