array_filter

(PHP 4 >= 4.0.6, PHP 5)

array_filter — Filters elements of an array using a callback function

說明

array array_filter ( array $input [, callback $callback ] )

Iterates over each value in the input array passing them to the callback function. If the callback function returns true, the current value from input is returned into the result array. Array keys are preserved.

參數

input

The array to iterate over

callback

The callback function to use

If no callback is supplied, all entries of input equal to FALSE (see converting to boolean) will be removed.

Return值

Returns the filtered array.

範例

Example#1 array_filter() example


<?php
function odd($var)
{
    return($var & 1);
}

function even($var)
{
    return(!($var & 1));
}

$array1 = array("a"=>1, "b"=>2, "c"=>3, "d"=>4, "e"=>5);
$array2 = array(6, 7, 8, 9, 10, 11, 12);

echo "Odd :\n";
print_r(array_filter($array1, "odd"));
echo "Even:\n";
print_r(array_filter($array2, "even"));
?>

上例將輸出：

Odd :
Array
(
    [a] => 1
    [c] => 3
    [e] => 5
)
Even:
Array
(
    [0] => 6
    [2] => 8
    [4] => 10
    [6] => 12
)

Example#2 array_filter() without callback


<?php

$entry = array(
             0 => 'foo',
             1 => false,
             2 => -1,
             3 => null,
             4 => ''
          );

print_r(array_filter($entry));
?>