PHP在沒有太多代碼的情況下根據另一個變數的值進行變數增量？

我正在嘗試根據其他變數值增加變數值，例如：

我有一個名為 $totalhousesleft 的變數...

我想根據我有多少 $totalhousesleft 來設定價格...

每次 totalhousesleft 減少 10 時，我想將變數 $currentprice 增加 1。

$totalhouses left 的起始值為 8000，每次下降 10，我設定 $currentprice 1 ...當前價格的起始值為 9...

就像是：

If ($totalhousesleft >= 8000) {$currentprice = 9;  $sellingprice = 8;}
If ($totalhousesleft >= 7990) {$currentprice = 10;  $sellingprice = 9;}
If ($totalhousesleft >= 7980) {$currentprice = 11;  $sellingprice = 10;}
If ($totalhousesleft >= 7970) {$currentprice = 12;  $sellingprice = 11;}

一直到房子剩下 1 個。如果有人可以給我看一個回圈或更短的代碼，我將不勝感激！

uj5u.com熱心網友回復：

@elias-soares 答案很接近，但缺少ceil……和解釋。

foreach ( [8000, 7995, 7990, 7985, 7980, 7975, 7970, 7965] as $totalhousesleft ) {
    $currentprice = 9   ((ceil(800 - ((min(8000, $totalhousesleft)) / 10))) * 1);
    $sellingprice = $currentprice - 1;
}

在這里試試：https ://onlinephp.io/c/68196

讓我們分解如何獲取$currentprice：

//$currentprice = ceil(9   (800 - (min(8000, $totalhousesleft) / 10)));

// get the lesser of 8000, or $totalhousesleft
// in other words, 8000 is the maximum number to calculate
$totalhousesleft = min(8000, $totalhousesleft);

// divide total houses left into number of tenth units
$tenth = $totalhousesleft / 10;

// since the price increases when the number of tenth units decreases,
// the unit factor is the difference between the max possible tenths 
// and tenths of the current total houses left
$tenthunit = 800 - $tenth;

// tenth unit is fractional for values not evenly divisible by 10,
// so round up
$tenthroundup = ceil($tenthunit);

// multiply the number of tenth units with the price per unit
$pricepertenth = $tenthroundup * 1; // 1 currency per tenth unit

// add the price per tenth cost to the base cost (9 currency)
$currentprice = 9   $pricepertenth;

獎勵：這可以在一個函式中實作：

function getPrices ($totalhousesleft, $baseprice = 9, $discount = 1, $priceperunit = 1, $maxtotal = 8000, $units = 10) {
    $currentprice = $baseprice   ((ceil(($maxtotal / $units) - ((min($maxtotal, $totalhousesleft)) / $units))) * $priceperunit);
    return [$currentprice, $currentprice - $discount];
}

foreach ( [8000, 7995, 7990, 7985, 7980, 7975, 7970, 7965] as $totalhousesleft ) {
    list($currentprice, $sellingprice) = getPrices($totalhousesleft);
}

在這里試試：https ://onlinephp.io/c/2672b

uj5u.com熱心網友回復：

可以為此使用orfor回圈。while我會使用for：

$iteration = 0;
for($x = 8000; $x > 0; $x = $x - 10){  
    if(empty($iteration)) {
        $iteration = $x/1000;
    }
    if ($totalhousesleft >= $x) { 
        $currentprice = $iteration;
        $sellingprice = $currentprice   1;
        break;
    }
    $iteration  ;
}
if(empty($currentprice)){
    $currentprice =  $iteration;
    $sellingprice = $currentprice   1;
}

這會迭代直到找到匹配項，然后退出回圈。價格基于它所在的迭代。

演示鏈接：https ://3v4l.org/Mm432 （針對邊緣情況 0-9 更新）

uj5u.com熱心網友回復：

您可以使用數學。

$currentprice = 9   (800 - (min(8000,$totalhousesleft)/10));
$sellingprice = $currentprice - 1;

標籤：php mysql 变量

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