PHP 多维数组 - 获取最后一个索引中元素的值？

Question

但不确定我的措辞是否正确，下面可以说明我正在努力实现更好的目标..

我有一个多维数组，我想在其中从数组 foreach 的最后一个索引捕获特定元素

数组：

正如您在括号中看到的（最后返回的），我需要 foreach“Something1.*) 中最后返回的指定元素内的值 - 具体来说，此字段包含日期 YYYY-MM-DD 并希望存储到 $ 以在别处重复使用。

希望这是有道理的，期待一些帮助！

Answer 1

如果您想从“Something1.*”中的每个元素中获取最新元素。你可以尝试这样的事情：

$array = [
    'Something' => [
        'Something1' => [
            [
                "@attributes" => array(
                    'DataID_1' => "Data",
                    "DataID_2" => "Data",
                    "DataID_3" => "Data",
                ),
                "Something1.1" => array(
                    "Something1.1.1" => array(
                        array(
                            "DataID_1" => "data",
                            "Date" => "YYYY-MM-DD",
                            "DataID_2" => "data",
                            "DataID_3" => "data",
                        ),
                        array(
                            "DataID_1" => "data",
                            "Date" => "YYYY-MM-DD",
                            "DataID_2" => "data",
                            "DataID_3" => "data",
                        ),
                        array(
                            "DataID_1" => "data",
                            "Date" => "YYYY-MM-DD last",
                            "DataID_2" => "data",
                            "DataID_3" => "data",
                        ),
                    ),
                ),
                "Something1.2" => array(
                    "Something1.2.1" => array(
                        array(
                            "DataID_1" => "data",
                            "Date" => "YYYY-MM-DD",
                            "DataID_2" => "data",
                            "DataID_3" => "data",
                        ),
                        array(
                            "DataID_1" => "data",
                            "Date" => "YYYY-MM-DD",
                            "DataID_2" => "data",
                            "DataID_3" => "data",
                        ),
                        array(
                            "DataID_1" => "data",
                            "Date" => "YYYY-MM-DD last",
                            "DataID_2" => "data",
                            "DataID_3" => "data",
                        ),
                    ),
                ),
            ],
        ],
    ],
];

$dates = [];
$something1 = $array['Something']['Something1'];

foreach ($something1 as $something_1) {                 // loop through 'Something1'
    foreach ($something_1 as $key => $something_1_1) {  // loop through each element of 'Something1'.
        if (str_starts_with($key, 'Something1.')) {     // if key starts with 'Something1.' PHP >= 8.0
            foreach ($something_1_1 as $key => $something_1_1_1) {
                $last_element = end($something_1_1_1);  // get last element of array
                $dates[] = $last_element['Date'];       // OUTPUT: YYYY-MM-DD last
            }
        }
    }
}

var_dump($dates); // This array will contain your dates.

// You can also use the following code to loop through dates:
foreach ($dates as $date) {
    echo $date; // OUTPUT: YYYY-MM-DD last
}

//OR access the dates in the following way:
$first_date = $dates[0];                    // get first date. and so on..
$last_date = $dates[count($dates) - 1];     // get last date.

请注意这些功能：
str_starts_with() 自 PHP8.0 起可用。
end() 将数组的内部指针设置为其最后一个元素。

Answer 2

你可以这样做。首先访问到所需的级别，然后选择每个数组的最后一个数组，检查它是否是一个数组，然后打印值“Date”。

假设示例中的多数组存储在名为$array的变量中：

foreach($array["something"]["Something1"] as $value) {
    foreach($value as $value1){
        if(is_array(end($value1))) {
            echo(end($value1)["Date"]);
        }
    }
}

如果您的多数组与您指出的示例存在偏差，您可能应该添加一些额外的验证。

已编辑 以显示将值保存到变量而不是打印它们的示例。

// First declare an array to store all values
$var = array();

// Then extract all values and save them into $var
foreach($array["something"]["Something1"] as $value) {
    foreach($value as $value1){
        if(is_array(end($value1))) {
            array_push($var, end($value1)["Date"]); // Add the value at the end of the $var array
        }
    }
}

// Finally you have all values stored into the $var array

// If you know the number of values, you can access them one by one
$var[num]; // Where 'num' is the position of the value stored into the array (0,1,2...)

// Or you can loop it

foreach ($var as $date) {
    // do whatever with each $date value
}

PHP 多维数组 - 获取最后一个索引中元素的值？

PHP Multidimensional Array - Get value of element in last index?

php

arrays

multidimensional-array