Having Your Cake - PHP

As you may have already guessed, defining an array variable takes place via the array() function - here's how:

<?
$desserts = array("chocolate mousse", "tiramisu", "apple pie", "chocolate
fudge cake");
?>

The rules for choosing an array variable name are the same as those for any other PHP variable - it must begin with a letter, and can optionally be followed by more letters and numbers.

Alternatively, you can define an array by specifying values for each element in the index notation, like this:

<?
$desserts[0] = "chocolate mousse";
$desserts[1] = "tiramisu";
$desserts[2] = "apple pie";
$desserts[3] = "chocolate fudge cake";
?>

Incidentally, you can omit the index numbers if you prefer - the following snippet is equivalent to the one above:

<?
$desserts[] = "chocolate mousse";
$desserts[] = "tiramisu";
$desserts[] = "apple pie";
$desserts[] = "chocolate fudge cake";
?>

If you'd prefer to use keys instead of numeric indices, the following examples should make you happier:

<?
$movies = array("romance" => "Moulin Rouge", "epic" => "Gladiator",
"action" => "The Terminator");
// this is equivalent
$movies["romance"] = "Moulin Rouge";
$movies["epic"] = "Gladiator";
$movies["action"] = "The Terminator";
?>

You can use the range() function to automatically create an array containing a range of elements:

<?
// returns the array ("30", "31", "32", "33", "34", "35", "36", "37", "38",
"39", "40")
$thirties = range(30, 40);
// returns the array ("i", "j", "k", "l", "m", "n", "o")
$alphabet = range("i", "o");
?>

You can add elements to the array in a similar manner - for example, if you wanted to add the element "apricot fritters" to the $desserts array, you would use this:

<?
$desserts[4] = "apricot fritters";
?>

and the array would now look like this:

<?
$desserts = array("chocolate mousse", "tiramisu", "apple pie", "chocolate
fudge cake", "apricot fritters");
?>

The same goes for non-numeric keys - adding a new key to the $movies array

<?
$movies["horror"] = "The Sixth Sense";
?>

alters it to read:

<?
$movies = array("romance" => "Moulin Rouge", "epic" => "Gladiator",
"action" => "The Terminator", "horror" => "The Sixth Sense");
?>

In order to modify an element of an array, you would simply assign a new value to the corresponding scalar variable. If you wanted to replace "chocolate fudge cake" with "chocolate chip cookies", you'd simply use

<?
$desserts[3] = "chocolate chip cookies";
?>

and the array would now read

<?
$desserts = array("chocolate mousse", "tiramisu", "apple pie", "chocolate
chip cookies", "apricot fritters");
?>

You can do the same with named keys - the statement

<?
$movies["action"] = "Rambo";
?>

further alters the $movies array to

<?
$movies = array("romance" => "Moulin Rouge", "epic" => "Gladiator",
"action" => "Rambo", "horror" => "The Sixth Sense");
?>

If it walks like an array, talks like an array and looks like an array, it must be an array...right? Well, you can always verify your suspicions with the is_array() function, which comes in handy if you need to test whether a particular variable is an array or not.

<?
// create array
$desserts = array("chocolate mousse", "tiramisu", "apple pie", "chocolate
fudge cake", "apricot fritters");
// returns true
echo is_array($desserts);
$desserts = "blueberry ice cream";
// returns false
echo is_array($desserts);
?>

>>> More PHP Articles          >>> More By Vikram Vaswani, (c) Melonfire

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