访问数组php中的特定数组

Question

首先是我是初学者:)

我正在为一个美术馆的网站工作（46位艺术家，每3件作品清单以及大量其他数据）

因此，我决定创建一个主要阵列，其中所有艺术家及其作品以阵列方式列在阵列中。 我开始了解如何使用foreach循环访问数组的各个部分。 但是，我很难弄清楚如何分别访问每个艺术家。

这是数组的一部分，并且foreach循环可以访问它

我试图实现的目标是能够使用一个非常大的阵列并能够分别访问每个艺术家的阵列。

       $artists = array(
            $sitnikov = array(
        $sitnikov[] = array(
        "artist" => "Vasily Sitnikov",
        "title" => '"'."Long Journey".'"',
        "year" => 1982,
        "media" => "Oil and tempera on plywood",
        "dimentions" => "H:" . 10 . " x W:" . 30.5 . "in",
        "availability" => "Sold",
        "thumb" => BASE_URL . "artists/vasily_sitnikov/images/ldpi/Thumb_Sitnikov_Vasily_Freedom.jpg",
        "lg" => BASE_URL . "artists/vasily_sitnikov/images/mdpi/Lg_Sitnikov_Vasily_Freedom.jpg"
        ),
        ),
        $slepishev = array(
        $slepishev[] = array(
        "artist" => "Anatoly Slepishev",
        "title" => '"'."Rider".'"',
        "year" => 1990,
        "media" => "Mixed media on paper",
        "dimentions" => "H:" . 19.5 . " x W:" . 25.5 . "in",
        "availability" => $available,
        "thumb" => BASE_URL .     "artists/anatoly_slepyshev/images/ldpi/Thumb_Anatoly_Slepishev_Rider.jpg",
        "lg" => BASE_URL . "artists/anatoly_slepyshev/images/mdpi/Lg_Anatoly_Slepishev_Rider.jpg",
        "literature" => "2011 Man’s Best Friends in the Works of Russian Artists Sloane Gallery of Art. ArtNet Online catalogue"
        ),
    $slepishev[] = array(
        "artist" => "Anatoly Slepishev",
        "title" => '"'."Lakeside".'"',
        "year" => 1991,
        "media" => "Watercolor on paper",
        "dimentions" => "H:" . 19.5 . " x W:" . 25.5 . "in",
        "availability" => $available,
        "thumb" => BASE_URL . "artists/anatoly_slepyshev/images/ldpi/Thumb_Anatoly_Slepyshev_Lakeside.jpg",
        "lg" => BASE_URL . "artists/anatoly_slepyshev/images/mdpi/Lg_Anatoly_Slepyshev_Lakeside.jpg",
        "literature" => "2011 Man’s Best Friends in the Works of Russian Artists Sloane Gallery of Art. ArtNet Online catalogue"
        ),
    $slepishev[] = array(
        "artist" => "Anatoly Slepishev",
        "title" => '"'."Rest".'"',
        "year" => 1991,
        "media" => "Watercolor on paper",
        "dimentions" => "H:" . 19.5 . " x W:" . 25.5 . "in",
        "availability" => $available,
        "thumb" => BASE_URL . "artists/anatoly_slepyshev/images/ldpi/Thumb_Anatoly_Slepyshev_Rest.jpg",
        "lg" => BASE_URL . "artists/anatoly_slepyshev/images/mdpi/Lg_Anatoly_Slepyshev_Rest.jpg"
        ))
);

echo "<pre>";
foreach ($artists as $artists_id => $artist_each) {
            echo $artist_id . "</br>";

        foreach ($artist_each as $artist_id => $artists_work) {
            echo 
            $artists_work["artist"] ."<br>"
            . $artists_work["title"] . "<br>"
            . $artists_work["year"] . "<br>" 
            . $artists_work["media"]. "<br>"
            . $artists_work["dimentions"] ."<br>"
            . $artists_work["availability"] ."<br>"
            .'"<img src ="' . $artists_work["thumb"] .'" /><br>'.
            '"<img src ="' . $artists_work["lg"] .'" /><br>'
            ;

        }
      }


      echo "</pre>";

Answer 1

数组的语法不完美。 您应该始终使用=>运算符在数组中创建键/值对。 键应为整数，字符串（例如"sitnikov" ）或具有整数或字符串值的现有变量（例如$sitnikov ）。 您不应该以[]结尾键：

$artists = array(
    "sitnikov" => array(
        0 => array(
            "artist" => "Vasily Sitnikov",
            "title" => '"'."Long Journey".'"',
            "year" => 1982,
            "media" => "Oil and tempera on plywood",
            "dimentions" => "H:" . 10 . " x W:" . 30.5 . "in",
            "availability" => "Sold",
            "thumb" => BASE_URL . "artists/vasily_sitnikov/images/ldpi/Thumb_Sitnikov_Vasily_Freedom.jpg",
            "lg" => BASE_URL . "artists/vasily_sitnikov/images/mdpi/Lg_Sitnikov_Vasily_Freedom.jpg"
        ),
    ),
    "slepishev" => array(
        0 => array(
            "artist" => "Anatoly Slepishev",
            "title" => '"'."Rider".'"',
            "year" => 1990,
            "media" => "Mixed media on paper",
            "dimentions" => "H:" . 19.5 . " x W:" . 25.5 . "in",
            "availability" => $available,
            "thumb" => BASE_URL .     "artists/anatoly_slepyshev/images/ldpi/Thumb_Anatoly_Slepishev_Rider.jpg",
            "lg" => BASE_URL . "artists/anatoly_slepyshev/images/mdpi/Lg_Anatoly_Slepishev_Rider.jpg",
            "literature" => "2011 Man’s Best Friends in the Works of Russian Artists Sloane Gallery of Art. ArtNet Online catalogue"
        ),
        1 => array(
            "artist" => "Anatoly Slepishev",
            "title" => '"'."Lakeside".'"',
            "year" => 1991,
            "media" => "Watercolor on paper",
            "dimentions" => "H:" . 19.5 . " x W:" . 25.5 . "in",
            "availability" => $available,
            "thumb" => BASE_URL . "artists/anatoly_slepyshev/images/ldpi/Thumb_Anatoly_Slepyshev_Lakeside.jpg",
            "lg" => BASE_URL . "artists/anatoly_slepyshev/images/mdpi/Lg_Anatoly_Slepyshev_Lakeside.jpg",
            "literature" => "2011 Man’s Best Friends in the Works of Russian Artists Sloane Gallery of Art. ArtNet Online catalogue"
        ),
        2 => array(
            "artist" => "Anatoly Slepishev",
            "title" => '"'."Rest".'"',
            "year" => 1991,
            "media" => "Watercolor on paper",
            "dimentions" => "H:" . 19.5 . " x W:" . 25.5 . "in",
            "availability" => $available,
            "thumb" => BASE_URL . "artists/anatoly_slepyshev/images/ldpi/Thumb_Anatoly_Slepyshev_Rest.jpg",
            "lg" => BASE_URL . "artists/anatoly_slepyshev/images/mdpi/Lg_Anatoly_Slepyshev_Rest.jpg"
        )
    )
);

如果在第一个foreach循环后立即更改行以echo $artists_id . "</br>";则嵌套的foreach循环将正常工作echo $artists_id . "</br>"; echo $artists_id . "</br>"; 。

Answer 2

数组的结构有点破损。

$artists = array(
    $sitnikov = array(
        $sitnikov[] = array(

您不需要第二个“ sitnikov”上的[]。 这是您要寻找的结构：

$artists = array (
    'sitnikov' => array(
        "artist" => "Vasily Sitnikov",
        "title" => '"'."Long Journey".'"'
    ),
    'slepishev' => array(
        "artist" => "Anatoly Slepishev",
        "title" => '"'."Lakeside".'"'
    )
);

然后，您可以执行以下操作：

foreach ( $artists as $artist => $values) {
    echo "Artist: " . $values['artist'] . "<br>";
    echo "Title: " . $values['title'] . "<br>";
    echo "<hr>";
}

这只是一个示例，因此使其适合您的需求。

Answer 3

我的天哪

不要误会我的意思：您对PHP语言的了解如此之浅，给您留下了深刻的印象。 但是，还有其他处理方法可以节省您大量的精力。

我可能是错的，但是您的代码使我认为，如果继续尝试，您可能会成为一个非常好的程序员。 这就是为什么我决定尝试让您开始做一些事情的原因。

---

当前方法的问题是直接在代码内部定义所有数据。 每次您想修改一些信息时，它都会迫使您使用不太友好的PHP语法。

正如其他答案所清楚显示的那样，您最终将获得难以理解且很难维护的代码。
拥有40名左右的艺术家，人数庞大，寻找或修改给定的信息将成为一场噩梦。

重点是从代码中解相关数据 。

正如我所看到的，诀窍是找到一种不需要大量PHP专业知识但仍然可以使您相对轻松地维护数据的解决方案。
超级专家将使用数据库，但这需要大量的投资才能学习如何处理PHP中这些繁琐的野兽。
我认为我们可以在这里解决一个简单的文本文件。 例如：

[artist]: Vasily Sitnikov

[picture]: Long Journey
year: 1982
media: Oil and tempera on plywood
dimentions: 10 30.5
availability: Sold

[artist]: Anatoly Slepishev

[picture]: Rider
year: 1990
media: Mixed media on paper
dimentions: 19.5 25.5
availability: Available
literature: 2011 Man’s Best Friends [...]

[picture]: Lakeside
year: 1991
media: Watercolor on paper
dimentions: 19.5 25.5
availability: Available
literature: 2011 Man’s Best Friends [...]

请注意，此“自制数据库”的一些字段与数组内容不同：

• thumb和url项目消失了，因为您可以自动计算它们
• 尺寸被简化为仅包含定义的可变部分（即原始宽度和高度，而不是整个“ W：xx H xx in。”字符串）。
  我们将生成一个“ pretty_dimensions”字段，其中包含完整的可显示字符串。
• 括号内的标记指定数据块的开始（基本上，您将需要一个艺术家数组，每个艺术家包含一组图片）
• 单个位或信息用名称表示，后跟:年份，尺寸等）。

现在，我们需要一些代码来读取此文件，并将其转换为与原始数组等效的文件。 我们还需要一些东西来将数据库的当前状态写回磁盘。

这是一个工作示例：

<?php

// -------------------
// Database parameters
// -------------------

// database default name
define ('DATABASE_NAME', "database.txt");

// database save directory
define ('SAVE_DIR', "save/");

// site root
define ('BASE_URL', "http://...."); // <-- *** PUT THE PROPER URL HERE


// ------------------------------
// main database reading function
// ------------------------------
function read_database ($filename = DATABASE_NAME)
{
    // list of properties that must be defined for each picture
    $mandatory_data = array (
        'year', 'dimentions', 'media', 'availability');
    // list of valid properties
    $allowed_data = array_merge ($mandatory_data, array (
        'literature'));

    // read the whole file into a string
    $file = file_get_contents ($filename);

    // split the file into lines
    $lines = explode ("\n", $file);

    // analyze each line
    $a = null; // current artist
    $p = null; // current picture
    $l = 0;    // current line number
    foreach ($lines as $line)
    {
        // keep track of line number for error reporting
        $l++;

        // eliminate trailing spaces and skip empty lines
        $line = trim ($line);
        if ($line == '') continue;

        // get the line type and value
        list ($type, $value) = explode (':', $line, 2);
        if ($value == null) panic ($line, "missing ':' delimiter");

        // decode the type
        $type = trim($type); // eliminate white spaces
        $value = trim($value);
        switch ($type)
        {
        case '[artist]':
            // create a new artist
            if (isset ($database[$value])) panic ($l, "artist '$value' defined more than once");
            $a = $value;
            $db[$a] = array();
            break;
        case '[picture]':
            // create a new picture for the current artist
            if ($a === null)         panic ($l, "picture defined before an artist was specified");
            if (isset ($db[$value])) panic ($l, "artist '$value' defined more than once");
            $p = $value;
            $db[$a][$p] = array();
            break;
        default:
            // all other values are simply stored as data
            // associated to the current picture of the current artist
            if ($a === null) panic ($l, "data defined before an artist was specified");
            if ($p === null) panic ($l, "data defined before a picture was specified");
            if (isset($db[$a][$p][$value])) panic ($l, "data '$type' defined more than once");
            $db[$a][$p][$type] = $value;
            break;
        }
    }

    // compute final data
    foreach ($db as $a => $pictures)
    {
        foreach ($pictures as $p => $picture)
        {
            // check mandatory data
            foreach ($mandatory_data as $data)
            {
                if (!isset ($picture[$data]))
                {
                    warning ($a,$p, "data '$data' not defined");
                    // set a dummy value to avoid errors in further processing
                    $picture[$data]="";
                }
            }

            // check allowed data
            foreach ($picture as $data => $value)
            {
                if (!in_array ($data, $allowed_data))
                {
                    warning ($a,$p, "invalid data name '$data'");
                }
            }

            // add picture name
            $picture['name'] = '"'.$p.'"';

            // compute pretty "dimentions" value
            @list ($w, $h, $extra) = explode (" ", $picture['dimentions']);
            if ($w == null || $h == null || $extra != null) warning ($a, $p, "invalid dimentions format");
            $picture['pretty_dimensions'] = "W: $w H: $h in.";

            // compute thumb and lg
            $uartist  = underscore_string ($a);
            $upicture = underscore_string ($p);
            $picture['thumb'] = BASE_URL . "artists/${uartist}/images/ldpi/Thumb_${uartist}_${upicture}.jpg";
            $picture['lg']    = BASE_URL . "artists/${uartist}/images/mdpi/Lg_${uartist}_${upicture}.jpg";

            // update current picture
            $db[$a][$p] = $picture;
        }
    }

    // done
    return $db;
}

function write_database ($db, $filename=DATABASE_NAME)
{
    // list of auto-computed properties
    $auto_data = array (
        'name', 'thumb', 'lg', 'pretty_dimensions');

    // make a safety copy of the current database state
    copy_to_safety ($filename);

    // compute new file contents
    $output = '';
    foreach ($db as $a => $pictures)
    {
        $output .= "[artist]:$a\n\n";
        foreach ($pictures as $p => $picture)
        {
            $output .= "[picture]:$p\n\n";
            foreach ($picture as $data => $value)
            {
                // skip auto-computed fields
                if (in_array ($data, $auto_data)) continue;

                $output .= "$data: $value\n";
            }
        }
    }

    // overwrite DB file with new contents
    file_put_contents ($filename, $output);
}

// copy a file to safety
function copy_to_safety ($filename)
{
    // nothing to do if there is no previous version
    if (!file_exists ($filename)) return;

    // create save directory if need be
    if (!file_exists(SAVE_DIR)) mkdir (SAVE_DIR, 0777, true);

    // copy the file
    $save_name = SAVE_DIR.$filename.date(" Y-M-d@H.i.s");
    file_put_contents ($save_name, file_get_contents ($filename));
}

// name computations
function underscore_string ($s)
{
    return str_replace (" ", "_", $s);
}

// error reporting
function panic ($line, $message)
{
    die ("FATAL ERROR in line <b>$line</b>: $message<br />");
}

function warning ($artist, $picture, $message)
{
    echo ("artist '$artist' picture '$picture': $message<br />");
}

// ----
// test
// ----

// display all sold pictures
function display_sold_pictures ($db)
{
    echo "<h1>sold pictures</h1>";
    echo "<table><tr><th>Artist</th><th>Picture</th><th>Year</th></tr>";
    foreach ($db as $a => $pictures)
        foreach ($pictures as $p => $picture)
        {
            if ($db[$a][$p]['availability'] != 'Sold') continue;
            echo "<tr><td>$a</td><td>$p</td><td>${picture['year']}</td></tr>";
        }
    echo "</table>";
}

// display sold pictures in the current DB
$db = read_database ();
display_sold_pictures ($db);

// mark every picture as sold
foreach ($db as $a => $pictures)
    foreach ($pictures as $p => $picture)
        $db[$a][$p]['availability'] = 'Sold';

// save the database
write_database ($db, "dummy.txt");

// display sold pictures in the modified DB
$db = read_database ("dummy.txt");
display_sold_pictures ($db);

?>

您可以从此处获取代码和示例数据库

我尽力使代码保持简单和（希望）可读。
随意询问是否不清楚（wanadoo dot fr的kuroi dot neko）

尽管这是一段有用的代码， 但这仍然只是一个示例 。

正确而强大的方法是使用本地数据库（通常是SQLite），而不是自己编写所有这些数据库处理代码。

但是，直接处理数据库访问可能是一项艰巨的任务。 希望这段代码可以作为中间步骤，以帮助您感觉如何完成工作。

下一步将是学习类和对象，以便您可以将这段代码转换为更令人愉快的用法。 我设计它的目的是使将数据库访问代码转换成一个类应该相对简单。

从那里您可以尝试实现一个真实的数据库。 但这不会在一天内完成:)。

Яооом：