Question

我有以下带有天数和总价的数组：

const input = [4,5,5,4,5,3,3,5,4,3];

const output = input.reduce((accum, x) => {
  accum[x] = accum[x] ? accum[x] + 1 : 1;
  return accum;
}, {});

console.log(output);

使用以下代码：

我得到：

foreach($blankarray as $rate){

    if ($rate['totalprice'] == '0'){
    } else {
        $firstrate = $rate['totalprice'];
        if ($firstrate != $previousrate) {
            $firstdate = $rate['day'];
            echo '<br>'.$firstdate; 
            echo '</br><font color="green"> <b>'.$firstrate .'</b></font>';
            $previousrate = $firstrate;
        }

总价变化时如何添加上一个日期，这样我就可以了：

Answer 1

尝试一下，我将您的数组重命名为$ rates并切换到for循环。

$rates_count = sizeof($rates);
$previous = 1;
for($i = 1; $i < $rates_count; ++$i) {
    if($rates[$i]['totalprice'] !== 0) {
        if($rates[$i]['totalprice'] > $rates[$previous]['totalprice']) {
            echo
                '<br />', "\n",
                $rates[$i]['day'], "\n",
                '<br />', "\n",
                $rates[$previous]['day'], "\n",
                '<br />', "\n",
                '<span style="color: green; font-weight: bold;">', $rates[$i]['totalprice'], '</span>', "\n";
            $previous = $i;
        }
    }
}

Answer 2

将上一个日期和价格保存在变量中。价格每变化一次，就打印前一个日期，上一个价格和当前日期。

$prev_date = null
foreach ($blankarray as $rate) {
    if ($rate['totalprice'] == 0) {
        // ignore zero rows
        continue;
    }
    if ($rate['day'] != $prev_date) {
        if ($prev_date) {
            echo "$prev_date<br><span style='color: green;'>$prev_price</span><br>";
        }
    }
    $prev_date = $rate['date'];
    $prev_price = $rate['totalprice'];
    echo $rate['date'] . "<br>";
}
// End the last group
echo "$prev_date<br><span style='color: green;'>$prev_price</span><br>";

Answer 3

此代码将为您提供所需的结果。它检查数组中的当前价格是否等于前一个价格或下一个价格（忽略所有0值），如果是，则输出价格：

$previousprice = -1;
$thisprice = -1;
$nextprice = $blankarray[0]['totalprice'];
$c = count($blankarray);
for ($i = 0; $i < $c; $i++) {
    $previousprice = $thisprice;
    $thisprice = $nextprice;
    $nextprice = ($i == $c - 1) ? -1 : $blankarray[$i+1]['totalprice'];
    if ($previousprice == 0 || $thisprice == 0 || $nextprice == 0) continue;
    if ($thisprice != $previousprice) {
        echo '<br>'.$blankarray[$i]['day']; 
    }
    if ($thisprice != $nextprice) {
        echo '<br>'.$blankarray[$i]['day']; 
        echo '<br><font color="green"> <b>'.$blankarray[$i]['totalprice'].'</b></font>' . "\n";        
    }
}

输出：

<br>01/08/2019<br>31/08/2019<br><font color="green"> <b>585</b></font> 
<br>01/09/2019<br>30/09/2019<br><font color="green"> <b>410</b></font> 
<br>01/10/2019<br>31/10/2019<br><font color="green"> <b>235</b></font>

Demo on 3v4l.org

PHP foreach循环通过多维数组输出按一个键->值分组

3 个答案: