You want to modify the size of an array, either by making it larger or smaller than its current size.
Use array_pad( ) to make an array grow:
// start at three $array = array('apple', 'banana', 'coconut'); // grow to five $array = array_pad($array, 5, '');
Now , count($array) is 5, and the last two elements, $array and $array, contain the empty string.
To reduce an array, you can use array_splice( ):
// no assignment to $array array_splice($array, 2);
This removes all but the first two elements from $array.
Arrays aren't a predeclared size in PHP, so you can resize them on the fly.
To pad an array, use array_pad( ). The first argument is the array to be padded. The next argument is the size and direction you want to pad. To pad to the right, use a positive integer; to pad to the left, use a negative one. The third argument is the value to be assigned to the newly created entries. The function returns a modified array and doesn't alter the original.
Here are some examples:
// make a four-element array with 'dates' to the right $array = array('apple', 'banana', 'coconut'); $array = array_pad($array, 4, 'dates'); print_r($array); Array (  => apple  => banana  => coconut  => dates ) // make a six-element array with 'zucchinis' to the left $array = array_pad($array, -6, 'zucchini'); print_r($array); Array (  => zucchini  => zucchini  => apple  => banana  => coconut  => dates )
Be careful: array_pad($array, 4, 'dates') makes sure an $array is at least four elements long; it doesn't add four new elements. In this case, if $array was already four elements or larger, array_pad( ) would return an unaltered $array.
Also, if you declare a value for a fourth element, $array:
$array = array('apple', 'banana', 'coconut'); $array = 'dates';
you end up with a four-element array with indexes 0, 1, 2, and 4:
Array (  => apple  => banana  => coconut  => dates )
PHP essentially turns this into an associative array that happens to have integer keys.
The array_splice( ) function, unlike array_pad( ), has the side effect of modifying the original array. It returns the spliced-out array. That's why you don't assign the return value to $array. However, like array_pad( ), you can splice from either the right or left. So calling array_splice( ) with a value of -2 chops off the last two elements from the end:
// make a four-element array $array = array('apple', 'banana', 'coconut', 'dates'); // shrink to three elements array_splice($array, 3); // remove last element, equivalent to array_pop() array_splice($array, -1); // only remaining fruits are apple and banana print_r($array); Array (  => apple  => banana )
4.6.4. See Also
Documentation on array_pad( ) at http://www.php.net/array-pad and array_splice( ) at http://www.php.net/array-splice .