Php 使数组元素复制它'；s上一个元素'；s值

我有一个数组，我想循环通过它，让它的元素使用PHP复制前面元素的值

array [
    17 => "x",
    16 => "x",
    15 => "x",
    14 => "108.7000",
    13 => "x",
    12 => "x",
    11 => "x",
    10 => "x",
    09 => "108.2635",
    08 => "x",
    07 => "x",
    06 => "x",
    05 => "x",
    04 => "x",
    03 => "x",
    02 => "x",
    01 => "x",
    00 => "x",
    23 => "x",
    22 => "x",
    21 => "x",
    20 => "x",
    19 => "x",
    18 => "x"
]

例如，输出应为：

array [
    17 => "108.7000",
    16 => "108.7000",
    15 => "108.7000",
    14 => "108.7000",
    13 => "108.2635",
    12 => "108.2635",
    11 => "108.2635",
    10 => "108.2635",
    09 => "108.2635",
    08 => "108.2635",
    07 => "108.2635",
    06 => "108.2635",
    05 => "108.2635",
    04 => "108.2635",
    03 => "108.2635",
    02 => "108.2635",
    01 => "108.2635",
    00 => "108.2635",
    23 => "108.2635",
    22 => "108.2635",
    21 => "108.2635",
    20 => "108.2635",
    19 => "108.2635",
    18 => "108.2635"
]

如您所见，14以上的键变为108.7000， 字母“x”将永远存在，这就是我想要检查的方式。 我无法理解这个问题，也许我甚至没有用正确的措辞来描述这个问题

---

看看09键，它的值是108.2635，下面是x，这意味着它们都应该复制09的值，而09到04之间的值也是x，这意味着它们也应该是108.2635，键14有它自己的值，在它上面是x值，这意味着它们应该复制14的值

如果不完全理解数组的结构，我只能提供以下方法：-

声明一个初始值为“x”的变量lastNumber

循环遍历数组，当您找到一个实际数字（！=“x”）时，将其存储在lastNumber中

用lastNumber替换后续的每个非数字（“x”）

最后，反转数组并再次执行步骤1、2和3

我知道这不是最优化的解决方案，但如果您了解正在发生的事情，您可以自己优化它

作为一个例子，考虑数组：-< /P>

[“x”、“x”、“x”、“34.34”、“x”、“x”、“20.02”、“x”]

• 在步骤1之后：-

lastNumber=“x”

• 步骤2和3：-

[“x”、“x”、“x”、“34.34”、“x”、“x”、“20.02”、“x”]

首先，

lastNumber的

值将为“34.34”，因此以下所有“x”将替换为“34.34”：-

[“x”、“x”、“x”、“34.34”、“34.34”、“34.34”、“20.02”、“x”]

接下来，

lastNumber的

值将是“20.02”，因此以下所有“x”都将替换为“20.02”：-

[“x”、“x”、“x”、“34.34”、“34.34”、“34.34”、“20.02”、“20.02”]

• 步骤4：-

现在，要将初始“x”替换为“34.34”，请按相反顺序在阵列上执行上述步骤

请随意提问。

试试这个-

$data = [ '17' => "x", '16' => "x", '15' => "x", '14' => "x", '13' => "108.7000", '12' => "x", '11' => "x", '10' => "x", '09' => "x", '08' => "x", '07' => "x", '06' => "x", '05' => "x", '04' => "x", '03' => "x", '02' => "x", '01' => "x", '00' => "x", '23' => "x", '22' => "x", '21' => "x", '20' => "x", '19' => "x", '18' => "108.2635"];

// Initially set reference as null. i.e. no reference value
$reference = null;
$group = [];

// Reverse the order so that we can traverse from bottom to up
$data = array_reverse($data, true);

// Traverse the array
foreach ($data as $key => $value)
{
    /**
     * If there is no reference by which we exchange the 'x' value
     * then assign keys at an undefined group.
     */
    if ($reference === null && $value === 'x')
    {
        $group['undefined'][] = $key;
    }
    elseif ($reference === null && $value !== 'x')
    {
        /**
         * If reference not yet set but value is not 'x'
         * then set the reference as the non-x value which we find just now.
         * And change the 'undefined' group by newly found non-x value
         */
        $reference = $value;

        if (!empty($group['undefined']))
        {
            $group[$reference] = $group['undefined'];
            unset($group['undefined']);
        }
    }
    elseif ($reference !== null && $value === 'x')
    {
        /**
         * If reference is set and value is 'x'
         * then push into the key into reference group.
         */
        $group[$reference][] = $key;
    }
    elseif ($reference !== null && $value !== 'x')
    {
        /**
         * If reference is not null and value is also not 'x'
         * then change the reference by newly found non-x value
         * and make a new group and push the key into the group
         */
        $reference = $value;
        $group[$reference][] = $key;
    }
}

/**
 * Traverse the group and exchange the 'x' values
 * from the group reference.
 */
foreach ($group as $value => $refs)
{
    foreach ($refs as $key)
    {
        $data[$key] = $value;
    }
}

/**
 * Finally get the original order of the data array
 *
 */
$data = array_reverse($data, true);

print_r($data);

---

因此，

x

指向最近的下一个值，或最近的previos？这

08=>“x”

x值是如何

108.2635

？@YosefTukachinsky不，x总是在那里，它可以在任何地方，基本上，x意味着这个元素应该复制一个不是xx的值，这个值被哪个条件替换了？为什么19以上和19以下的元素都有相同的值-108.2635？@SajeedAhamed它工作得很好，只是当最后一个键的值不是x时出现问题，那么它会给出错误，在这种情况下，假设键18有一个值，但它不是XT，那么我就不会得到任何错误。它正在工作。我在SajeebAhamed为正值，当我给最后一个元素一个值时，我得到了这个错误：未定义的索引：未定义的

$data=['17'=>“x”、'16'=>“x”、'15'=>“x”、'14'=>“x”、'13'=>“108.7000”、'12'=>“x”、'11'=>“x”、'10'=>“x”、'09'=>“x”、'08'=>“x”、'07'=>“x”、'06'=>“x”、'05'>“x”、'03'>“x”、'01'=>“x”、'00'=>“x”、'23'=>“x”、'22'=>“x”、'21'=>“x”、'20'=>“x”、'19'=>“x”、'18'=>“108.2635”]；