ZEND PHP 5 Certification STUDY GUIDE

50 ” Arrays
$a = array (’4’ => 5, ’a’ => ’b’);
$a[] = 44; // This will have a key of 5
i
Note that array keys are case-sensitive, but type insensitive. Thus, the key ’A’ is different
from the key ’a’, but the keys ’1’ and 1 are the same. However, the conversion is
only applied if a string key contains the traditional decimal representation of a number;
thus, for example, the key ’01’ is not the same as the key 1.
Multi-dimensional Arrays
Since every element of an array can contain any type of data, the creation of multidimensional
arrays is very simple: to create multi-dimensional arrays, we simply
assign an array as the value for an array element. With PHP, we can do this for one or
more elements within any array—thus allowing for infinite levels of nesting.
$array = array();
$array[] = array(
’foo’,
’bar’
);
$array[] = array(
’baz’,
’bat’
);
echo $array[0][1] . $array[1][0];
Our output from this example is barbaz. As you can see, to access multi-dimensional
array elements, we simply “stack” the array operators, giving the key for the specific
element we wish to access in each level.
Licensed to 482634 - Amber Barrow (itsadmin@deakin.edu.au)
Unravelling Arrays
It is sometimes simpler to work with the values of an array by assigning them to
individual variables. While this can be accomplished by extracting individual ele-