如何增加 php 阵列？

Question

我正在开发 jQuery 拖放游戏并从 csv 文件中提取信息，例如正在运行的图像、年份和文本：

$rows = file('Book1.csv');
$len = count($rows);
$rand = array();
while (count($rand) < 5) {
    $r = rand(0, $len);
    if (!in_array($r, $rand)) {
        $rand[] = $r;
    }
}
echo 'var cardDeck = [';
foreach ($rand as $r) {
    $csv = $rows[$r];
    $data = str_getcsv($csv);
    echo "{\n";
    echo "'image':'".$data[1]."',\n"; 
    echo "'year':'".$data[0]."',\n"; 
    echo "'hint':'".$data[3]."',\n"; 
    echo "'caption':'".$data[2]."'"; 
    echo "\n},\n";
}
echo "];";

但是我遇到的问题是，我正在尝试创建 5 个新的 arrays 使用增加变量名称的 for 循环，并将年份值设置为 arrays 已经从 Z628CB5675FF524F3E719FE8FE833

foreach ($rand as $r) {
    $csv = $rows[$r];
    $data = str_getcsv($csv);
    for ($i = 1; $i < 5; $i++) {
        $varToEcho = "correct_dropzone$i"; // become correct_dropzone1,correct_dropzone2,etc.
        echo "var ".$varToEcho." = new Array('".$data[0]."');\n"; 
    }   
}

我在找什么：

var correct_dropzone1 = new Array('1845');
var correct_dropzone2 = new Array('1835');
var correct_dropzone3 = new Array('1586');
var correct_dropzone4 = new Array('1912');
var correct_dropzone5 = new Array('1969');

但我的 output 是：

var correct_dropzone1 = new Array('1845');
var correct_dropzone2 = new Array('1845');
var correct_dropzone3 = new Array('1845');
var correct_dropzone4 = new Array('1845');
var correct_dropzone1 = new Array('1835');
var correct_dropzone2 = new Array('1835');
var correct_dropzone3 = new Array('1835');
var correct_dropzone4 = new Array('1835');
var correct_dropzone1 = new Array('1586');
var correct_dropzone2 = new Array('1586');
var correct_dropzone3 = new Array('1586');
var correct_dropzone4 = new Array('1586');
var correct_dropzone1 = new Array('1912');
var correct_dropzone2 = new Array('1912');
var correct_dropzone3 = new Array('1912');
var correct_dropzone4 = new Array('1912');
var correct_dropzone1 = new Array('1822');
var correct_dropzone2 = new Array('1822');
var correct_dropzone3 = new Array('1822');
var correct_dropzone4 = new Array('1822');

Answer 1

您不需要嵌套循环，只需一个循环。 使用循环的索引 as 创建变量的数字后缀。

foreach ($rand as $i => $r) {
    $csv = $rows[$r];
    $data = str_getcsv($csv);
    $varToEcho = "correct_dropzone" . ($i + 1);
    $valToEcho = json_encode(array($data[0]));
    echo "var $varToEcho = $valToEcho;\n";
}

我还展示了如何使用json_encode()将 PHP 值转换为 JavaScript 文字，而不是手动构建它。

此外，带有数字后缀的变量通常表明您应该使用数组而不是单独的变量。 您可以将correct_dropzone一个数组。

$dropzones = array();
foreach ($rand as $r) {
    $csv = $rows[$r];
    $data = str_getcsv($csv);
    $dropzones[] = array($data[0]);
}
echo "var correct_dropzones = " . json_encode($dropzones) . ";";

对cardDeck做类似的事情：

$cardDeck = array();
foreach ($rand as $r) {
    $csv = $rows[$r];
    $data = str_getcsv($csv);
    $cardDeck[] = array(
        'image' => $data[1],
        'year' => $data[0],
        'hint' => $data[3],
        'caption' => $data[2]
    );
}
echo "var cardDeck = " . json_encode($cardDeck) . ";";

您可以对两个变量使用相同的循环。