PHP Tutorial - PHP arsort() Function
Definition
The arsort() function reverse sorts array by its values while preserving the keys.
Note
The arsort() function is used to sort associative array.
It is the associative array version of rsort().
Syntax
PHP arsort() Function has the following syntax.
bool arsort ( array &arr [, int options] )Parameter
| Parameter | Is Required | Description |
|---|---|---|
| array | Required. | Array to sort |
| sortingtype | Optional. | How to compare the array elements/items. |
Possible values for sortingtype:
| Value | Description |
|---|---|
| 0 = SORT_REGULAR | Default. Compare items normally (don't change types) |
| 1 = SORT_NUMERIC | Compare items numerically |
| 2 = SORT_STRING | Compare items as strings |
| 3 = SORT_LOCALE_STRING | Compare items as strings, based on current locale |
| 4 = SORT_NATURAL | Compare items as strings using natural ordering |
| 5 = SORT_FLAG_CASE | can be combined bitwise OR with SORT_STRING or SORT_NATURAL to sort strings case-insensitively |
This is the opposite of the asort().
Example 1
Reverse sorts array by its values
<?PHP
$capitalcities['Key1'] = 'Z';
$capitalcities['Key2'] = 'X';
$capitalcities['Key3'] = 'Y';
arsort($capitalcities);
print_r($capitalcities);
?>
The ksort() can take custom function for determining the sequence.
The code above generates the following result.
Example 2
Reverse sorts array by its values and output its keys and values
<?php
$fruits = array("A", "B", "C", "java2s.com");
arsort($fruits);
foreach ($fruits as $key => $val) {
echo "fruits[" . $key . "] = " . $val . "\n";
}
?>
The code above generates the following result.
Example 3
arsort() example using case-insensitive natural ordering
<?php// w w w. ja v a 2s .c o m
$fruits = array(
"PHP1", "php2", "PHP3", "php20"
);
arsort($fruits, SORT_NATURAL | SORT_FLAG_CASE);
foreach ($fruits as $key => $val) {
echo "fruits[" . $key . "] = " . $val . "\n";
}
?>
The code above generates the following result.
