Page 175 - Beginning PHP 5.3

Chapter 6: Arrays
explode() is often useful when you need to read in a line of comma - or tab - separated data from a file
and convert the data to an array of values.

Other useful string - to - array functions include preg_split() for splitting based on regular expres-
sions (see Chapter 18 ), and str_split() for splitting a string into characters (or into fixed - length
character chunks) — see http://www.php.net/manual/en/function.str - split.php for
details.

If you want to do the opposite of explode() and glue array elements together into one long string,

use — you guessed it — implode() . This takes two arguments: the string of characters to place between
each element in the string, and the array containing the elements to place in the string. For example, the
following code joins the elements in $fruitArray together to form one long string, $fruitString ,
with each element separated by a comma:
$fruitArray = array( “apple”, “pear”, “banana”, “strawberry”, “peach” );
$fruitString = implode( “,”, $fruitArray );
// Displays “apple,pear,banana,strawberry,peach”

echo $fruitString;

Converting an Array to a List of Variables
The final array - manipulation tool you learn about in this chapter is list() . This construct provides an
easy way to pull out the values of an array into separate variables. Consider the following code:

$myBook = array( “The Grapes of Wrath”, “John Steinbeck”, 1939 );
$title = $myBook[0];
$author = $myBook[1];
$pubYear = $myBook[2];
echo $title . “ < br/ > ”; // Displays “The Grapes of Wrath”
echo $author . “ < br/ > ”; // Displays “John Steinbeck”
echo $pubYear . “ < br/ > ”; // Displays “1939”

It works, but is rather long - winded. This is where list() comes into play. You use it as follows:

$myBook = array( “The Grapes of Wrath”, “John Steinbeck”, 1939 );
list( $title, $author, $pubYear ) = $myBook;

echo $title . “ < br/ > ”; // Displays “The Grapes of Wrath”
echo $author . “ < br/ > ”; // Displays “John Steinbeck”

echo $pubYear . “ < br/ > ”; // Displays “1939”
Note that list() only works with indexed arrays, and it assumes the elements are indexed
consecutively starting from zero (so the first element has an index of 0 , the second has an index of 1 ,
and so on).

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