定義
array_map - 對給定的諸多陣列使用回呼函式
描述
array_map ( callable $callback , array $array1 [, array $... ] ) : array
將傳入的陣列按對應值傳遞給回呼函式，回呼函式處理結果組成新的陣列作為回傳值回傳；
傳入的陣列個數必須與回呼函式的形參個數相同，
示例一
<?php
function show_Spanish($n, $m)
{
return "The number {$n} is called {$m} in Spanish";
}
$a = [1, 2, 3];
$b = ['uno', 'dos', 'tres'];
$c = array_map('show_Spanish', $a, $b);
print_r($c);
?>
將輸出：
Array
(
[0] => The number 1 is called uno in Spanish
[1] => The number 2 is called dos in Spanish
[2] => The number 3 is called tres in Spanish
)
示例二
如果傳入多個陣列，每個陣列的長度必須相同，否組，短的陣列會用空值擴充成對應長度，
這個函式可用于構建一個多維陣列（ zip operation of arrays ），像下面這樣
<?php
$a = [1, 2, 3];
$b = ['one', 'two', 'three'];
$c = ['uno', 'dos', 'tres'];
$d = array_map(null, $a, $b, $c);
print_r($d);
?>
將輸出：
Array
(
[0] => Array
(
[0] => 1
[1] => one
[2] => uno
)
[1] => Array
(
[0] => 2
[1] => two
[2] => dos
)
[2] => Array
(
[0] => 3
[1] => three
[2] => tres
)
)
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標籤：PHP
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