Best method for sum two arrays [closed]

问题:

I have two arrays:

$a = array(10, 2, 5, 10, 0);
$b = array(1, 20, 11, 8, 3);

I need to sum up and get the result:

$c = array(11, 22, 16, 18, 3);

Any suggestions on how do this without "foreach"?

回答1:

a simple approach could be

$c = array_map(function () {
    return array_sum(func_get_args());
}, $a, $b);

print_r($c);

Or if you could use PHP5.6, you could also use variadic functions like this

$c = array_map(function (...$arrays) {
    return array_sum($arrays);
}, $a, $b);

print_r($c);

Output

Array
(
    [0] => 11
    [1] => 22
    [2] => 16
    [3] => 18
    [4] => 3
)

回答2:

Try like

$c = array();
foreach (array_keys($a + $b) as $key) {
    $c[$key] = $a[$key] + $b[$key];
}

回答3:

There's no way you can do that without the "foreach" as you asked for, you need to loop on both arrays to get the respective values.

A function using the foreach would be :

function sum_arrays($array1, $array2) {
    $array = array();
    foreach($array1 as $index => $value) {
        $array[$index] = isset($array2[$index]) ? $array2[$index] + $value : $value;
    }
    return $array;
}

Now you just need to do :

$c = sum_arrays($a, $b);

回答4:

$c = array();
for($i=0;$i<count($a);$i++) {
  $c[$i] = $a[$i]+$b[$i];
}