It sorts an array by keys using a user-defined comparison function

Example

<?php
function func($a, $b)
{
if ($a == $b) {
return 0;
}
return ($a < $b) ? -1 : 1;
}
echo “<pre>”;
$array = array(1, 7, 5, 8, 4);
usort($array, “func”);
print_r($array);
?>

Output

Array
(
[0] => 1
[1] => 4
[2] => 5
[3] => 7
[4] => 8
)

It sorts an array with a user-defined comparison function and maintain index association

Example

<?php
echo “<pre>”;
$lan = array(“PHP”,”ASP”,”JSP”);
uasort($lan);
print_r($lan);
?>

Output

Array
(
[0] => PHP
[1] => ASP
[2] => JSP
)

It sorts the array

Example

<?php
echo “<pre>”;
$lan = array(“PHP”,”JSP”,”ASP”);
sort($lan);
print_r($lan);
?>

Output

Array
(
[0] => ASP
[1] => JSP
[2] => PHP
)

It an alias of count() and returns the number of elements

Example

<?php
$lan = array(“PHP”,”JSP”,”ASP”);
echo sizeof($lan);
?>

Output

3

It shuffles the array

Example

<?php
echo “<pre>”;
$lan = array(“PHP”,”JSP”,”ASP”);
shuffle($lan);
print_r($lan);
?>

Output

Array
(
[0] => ASP
[1] => PHP
[2] => JSP
)

It  sorts the array in reverse order

Example

<?php
echo “<pre>”;
$lan = array(“PHP”,”JSP”,”ASP”);
rsort($lan);
print_r($lan);
?>

Output

Array
(
[0] => PHP
[1] => JSP
[2] => ASP
)

it  set the internal pointer of an array to its first element

Example

<?php
$lan = array(“PHP”,”JSP”,”ASP”);
next($lan);
next($lan);
echo reset($lan);
?>

Output

PHP

It can be used to create an array containing a range of elements

Example

<?php
echo “<pre>”;
$array = range(3, 7);
print_r($array);
?>

Output

Array
(
[0] => 3
[1] => 4
[2] => 5
[3] => 6
[4] => 7
)

It rewinds the internal array pointer

Example

<?php
$lan = array(“PHP”,”JSP”,”ASP”);
next($lan);
echo prev($lan);
?>

Output

PHP