PHP arsort() Function
In this chapter you will learn:
- Definition for PHP arsort() Function
- Note for PHP arsort() Function
- Syntax for PHP arsort() Function
- Parameter for PHP arsort() Function
- Example - reverse sorts array by its values
- Example - reverse sorts array by its values and output its keys and values
- Example - arsort() example using case-insensitive natural ordering
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//j a va 2 s. c o m
$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/* j a v a 2 s. c om*/
$fruits = array("A", "B", "C", "java2s.com");
arsort($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// j a v a 2s .com
$fruits = array(
"PHP1", "php2", "PHP3", "php20"
);
arsort($fruits, SORT_NATURAL | SORT_FLAG_CASE);
foreach ($fruits as $key => $val) {
echo "fruits[" . $key . "] = " . $val . "\n";
}
?>
The code above generates the following result.
Next chapter...
What you will learn in the next chapter:
- Definition for PHP asort() Function
- Note for PHP asort() Function
- Syntax for PHP asort() Function
- Parameter for PHP asort() Function
- Example - Sort an associative array in ascending order, according to the value:
- Example - asort() works by directly changing the value you pass in
Home » PHP Tutorial » PHP Array Functions