Microsoft Word - Core PHP Programming Using PHP to Build Dynamic Web Sites

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Listing 5.6 Creating and Referencing a Multidimensional Array


<?
$Cities = array(
"California"=>array(
"Martinez",
"San Francisco",
"Los Angeles"
),
"New York"=>array(
"New York",
"Buffalo"
)


print($Cities["California"][1]);
?>


Casting Arrays


You can cast an array as another data type to get results of various usefulness. When you
cast an array as an integer, double or boolean, you will get a value of 1. When you cast an
array as a string, you will get the word Array. This is useful as an indicator of when you
have mistakenly used an array as a string. An array will be promoted to a string
containing Array if you use it in a context that demands a string, such as in a print
statement. You can't use an array in a context that expects a number, such as with the
addition operator. This will cause an error. Listing 5.7 explores casting an array as other
data types.


The most useful cast of an array you can perform is to an object. The elements of the
array will become properties of the object. However, elements indexed by values illegal
as property names will remain inaccessible. These values are not lost, and if you recast
the variable as an array, they will become available again. Objects are discussed in
Chapter 6.


Listing 5.7 Casting Arrays as Other Data Types

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