array_reduce
Iteratively reduce the array to a single value using a callback function
Syntax
array_reduce ( array $array , callable $callback [, mixed $initial = NULL ] ) : mixed
Parameters
array
The input array.
callback ( mixed $carry , mixed $item ) : mixed
carry
Holds the return value of the previous iteration; in the case of the first iteration it instead holds the value of initial.
item
Holds the value of the current iteration.
initial
If the optional initial is available, it will be used at the beginning of the process, or as a final result in case the array is empty.
Return
Returns the resulting value.
Examples
array callback
<?
function myfunction($carry, $item)
{
$carry += $item;
return $carry;
}
$array = array(0, 1, 2, 3, 4);
$callback = "myfunction";
$return = array_reduce($array, $callback);
print_r($return);
?>
10
initial | Null
<?
function myfunction($carry, $item)
{
$carry += $item;
return $carry;
}
$array = array(0, 1, 2, 3, 4);
$callback = "myfunction";
$initial = null;
$return = array_reduce($array, $callback, $initial);
print_r($return);
?>
10
initial | Not Null
<?
function myfunction($carry, $item)
{
$carry += $item;
return $carry;
}
$array = array(0, 1, 2, 3, 4);
$callback = "myfunction";
$initial = 5;
$return = array_reduce($array, $callback, $initial);
print_r($return);
?>
15
initial | Empty Array
<?
function myfunction($carry, $item)
{
$carry += $item;
return $carry;
}
$array = array();
$callback = "myfunction";
$initial = "empty";
$return = array_reduce($array, $callback, $initial);
print_r($return);
?>
empty