array_sum
(PHP 4 >= 4.0.4, PHP 5)
array_sum — Вычислить сумму значений массива
Описание
array_sum() возвращает сумму значений массива. Полученный результат будет иметь тип integer или float.
Пример #1 Пример использования array_sum()
<?php
$a = array(2, 4, 6, 8);
echo "sum(a) = " . array_sum($a) . "\n";
$b = array("a" => 1.2, "b" => 2.3, "c" => 3.4);
echo "sum(b) = " . array_sum($b) . "\n";
?>
Программа выведет:
sum(a) = 20 sum(b) = 6.9
Замечание: PHP более ранних, чем 4.2.1, версий модифицировал переданный в качестве аргумента массив и конвертировал строки в числа (что в большинстве случаев означало конвертирование в 0).
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Коментарии
array_sum converts strings to integer and array_sum(2,'2') returns 4.
I had no idea.
If you want to calculate the sum in multi-dimensional arrays:
<?php
function array_multisum(array $arr): float {
$sum = array_sum($arr);
foreach($arr as $child) {
$sum += is_array($child) ? array_multisum($child) : 0;
}
return $sum;
}
?>
Example:
<?php
$data =
[
'a' => 5,
'b' =>
[
'c' => 7,
'd' => 3
],
'e' => 4,
'f' =>
[
'g' => 6,
'h' =>
[
'i' => 1,
'j' => 2
]
]
];
echo array_multisum($data);
//output: 28
?>
<?php
//you can also sum multidimentional arrays like this;
function arraymultisum(array $arr){
$sum=null;
foreach($arr as $child){
$sum+=is_array($child) ? arraymultisum($child):$child;
}
return $sum;
}
echo arraymultisum(array(1,4,5,[1,5,8,[4,5,7]]));
//Answer Will be
//40
?>
Notably the function converts strings to float and ignores strings if they are not convertable:
<?php
$a = array("String", 2, 4, 6, 8);
echo "sum(a) = " . array_sum($a) . "\n";
$b = array("12.3456", 2, 4, 6, 8);
echo "sum(b) = " . array_sum($b) . "\n";
?>
sum(a) = 20
sum(b) = 32.3456
array_sum() doesn't "ignore strings if they are not convertible", it converts them to zero. array_product() does the same thing, where the difference between "ignoring" and "converting to zero" is much more obvious.If you have a case where your array has int in strings, it sums them up as if there were only int in the array!function sum_mix($a)
{
return array_sum($a);
}
var_dump(sum_mix([9, 3, '7', '3']));
Response will be int(22)