arrays - Inteligent subtraction of values in array (php)

Question

PHP Language

Is it difficult to write a function to subtraction value from each [Amount] values in array ?, all that until subtraction value is appeased ?.

Example what i need (before subtraction):

[MainStockAddedArr] => Array
                        (
                            [0] => Array
                                (
                                    [Amount] => 10
                                    [Price] => 19.44
                                )

                            [1] => Array
                                (
                                    [Amount] => 15
                                    [Price] => 15.55
                                )

                            [2] => Array
                                (
                                    [Amount] => 20
                                    [Price] => 11.55
                                )

                            [3] => Array
                                (
                                    [Amount] => 30
                                    [Price] => 11.10
                                )

                        )

Value to subtraction is for example 30 pieces. So i would need to have results in array look like this:

    [MainStockAddedArr] => Array
                        (
                            [0] => Array
                                (
                                    [Amount] => 0
                                    [Price] => 19.44
                                )

                            [1] => Array
                                (
                                    [Amount] => 0
                                    [Price] => 15.55
                                )

                            [2] => Array
                                (
                                    [Amount] => 15
                                    [Price] => 11.55
                                )

                            [3] => Array
                                (
                                    [Amount] => 30
                                    [Price] => 11.10
                                )

                        )

In above example, two values are changed to 0 so that gives 25 pieces already been taken, on third value only 5 has been taken, that gives 30 pieces so no more is needed. This is just example, subtraction value will be dynamic, from a loop which is above this one.

In situation where subtraction value would be greater than in whole array (sum [Amounts]), else is needed.

标签： arrayssubtraction

Answer 1

这是FIFO（先进先出）方法的示例。您可以尝试，如果需要也可以进行一些更正。

作为常规功能：

function fifo($argArray, $argValue, $colName = 'amount') {

    // initialize
    $total = is_numeric($argValue) ? $argValue : 0;
    $i = 0;

    // check for input amount (total)
    if ($total > 0) {

        // process the input array 
        foreach ($arrArray as $key => $v) {

            // initialize amount value
            $amount = $remains = $v[$colName] ?: 0;

            // check for amount availability
            if ($amount) {
                // increment counter
                $i++;

                // calculate amount value remains
                $remains -= $amount > $total ? $total : $amount;

                // set amount value remains in array
                $argArray[$key][$colName] = $remains;

                // calculate last total remains
                $total -= $amount - $remains;

                // when total remains is zero then exit the loop process
                if ($total === 0) break;
            }
        }
    }

    // return count of rows been used and total remains
    return ['rowsCount' => $i, 'totalRemains' => $total];
}

用法：

$result = fifo(<argArray>, <argValue>, [<columnName>]);

作为一个班级：

namespace AnyNamespace;

class AnyClass extend \ArrayObject {

public function getFifo($argValue, $colName = 'amount') {
    return $this::fifo($this, $argValue, $colName);
}

public static function fifo($argArray, $argValue, $colName = 'amount') {

    // initialize
    $total = is_numeric($argValue) ? $argValue : 0;
    $i = 0;

    // check for input amount (total)
    if ($total > 0) {

        // process the input array 
        foreach ($arrArray as $key => $v) {

            // initialize amount value
            $amount = $remains = $v[$colName] ?: 0;

            // check for amount availability
            if ($amount) {
                // increment counter
                $i++;

                // calculate amount value remains
                $remains -= $amount > $total ? $total : $amount;

                // set amount value remains in array
                $argArray[$key][$colName] = $remains;

                // calculate last total remains
                $total -= $amount - $remains;

                // when total remains is zero then exit the loop process
                if ($total === 0) break;
            }
        }
    }

    // return count of rows been used and total remains
    return ['rowsCount' => $i, 'totalRemains' => $total];
}
}

用法：

use AnyNamespace;
...
$result = AnyClass::fifo(<argArray>, <argValue>, [<columnName>]);

或者

use AnyNamespace;
...
$anyClass = new AnyClass(<inputArray>);

$result = $anyClass->getFifo(<argValue>, [<columnName>]);