uasort
Description
The uasort of Array for PHP sort an array with a user-defined comparison function and maintain index association.
Syntax
uasort(
array &$array,
callable $callback
): trueParameters
array
The input array.
callback
The comparison function must return an integer less than, equal to, or greater than zero if the first argument is considered to be respectively less than, equal to, or greater than the second.
callback(
mixed $a,
mixed $b
): inta
first argument
b
second argument
Caution: Returning non-integer values from the comparison function, such as float, will result in an internal cast to integer of the callback's return value. So values such as 0.99 and 0.1 will both be cast to an integer value of 0, which will compare such values as equal.
Return
Always returns true.
Examples
1
<?
function myfunction($a, $b)
{
if($a < $b)
{
return -1;
}
else if($a > $b)
{
return 1;
}
else
{
return 0;
}
}
$array = array('a' => 4, 'b' => 8, 'c' => -1, 'd' => -9, 'e' => 2, 'f' => 5, 'g' => 3, 'h' => -4);
$callback = "myfunction";
print_r($array);
uasort($array, $callback);
print_r($array);
?>Array
(
[a] => 4
[b] => 8
[c] => -1
[d] => -9
[e] => 2
[f] => 5
[g] => 3
[h] => -4
)
Array
(
[d] => -9
[h] => -4
[c] => -1
[e] => 2
[g] => 3
[a] => 4
[f] => 5
[b] => 8
)
2
<?
function myfunction($a, $b)
{
if($a < $b)
{
return 1;
}
else if($a > $b)
{
return -1;
}
else
{
return 0;
}
}
$array = array('a' => 4, 'b' => 8, 'c' => -1, 'd' => -9, 'e' => 2, 'f' => 5, 'g' => 3, 'h' => -4);
$callback = "myfunction";
print_r($array);
uasort($array, $callback);
print_r($array);
?>Array
(
[a] => 4
[b] => 8
[c] => -1
[d] => -9
[e] => 2
[f] => 5
[g] => 3
[h] => -4
)
Array
(
[b] => 8
[f] => 5
[a] => 4
[g] => 3
[e] => 2
[c] => -1
[h] => -4
[d] => -9
)
Links
Array
- array
- array_change_key_case
- array_chunk
- array_column
- array_combine
- array_count_values
- array_diff
- array_diff_assoc
- array_diff_key
- array_diff_uassoc
- array_diff_ukey
- array_fill
- array_fill_keys
- array_filter
- array_flip
- array_intersect
- array_intersect_assoc
- array_intersect_key
- array_intersect_uassoc
- array_intersect_ukey
- array_key_exists
- array_key_first
- array_key_last
- array_keys
- array_map
- array_merge
- array_merge_recursive
- array_multisort
- array_pad
- array_pop
- array_product
- array_push
- array_rand
- array_reduce
- array_replace
- array_replace_recursive
- array_reverse
- array_search
- array_shift
- array_slice
- array_splice
- array_sum
- array_udiff
- array_udiff_assoc
- array_udiff_uassoc
- array_uintersect
- array_uintersect_assoc
- array_uintersect_uassoc
- array_unique
- array_unshift
- array_values
- array_walk
- array_walk_recursive
- arsort
- asort
- compact
- count
- current
- end
- extract
- in_array
- key
- key_exists
- krsort
- ksort
- list
- natcasesort
- natsort
- next
- pos
- prev
- range
- reset
- rsort
- shuffle
- sizeof
- sort
- uksort
- usort
