數組中的兩個索引

Question

我想做這樣的事情：

<?php
    $times[monday] = ['7-10', '3-5', '1-6'];
    $times[tuesday] = ['5-9', '12-15', '19-22'];
    echo $times[monday][2]
?>

此代碼將回顯3-5 ，因為這是數組$times[monday]的第二項。

但是，這只是錯誤：

Notice: Use of undefined constant monday - assumed 'monday' in /var/www/sch/index.php on line 2

Notice: Use of undefined constant tuesday - assumed 'tuesday' in /var/www/sch/index.php on line 3

Notice: Use of undefined constant monday - assumed 'monday' in /var/www/sch/index.php on line 4

Answer 1

<?php
    $times['monday'] = array('7-10', '3-5', '1-6');
    $times['tuesday'] = array('5-9', '12-15', '19-22');
    echo $times['monday'][2]
?>

您將想引用數組字符串元素標識符（例如“ monday”）並使數組多維，如圖所示。

如果不帶引號，則將字符串monday視為常量。

請注意代碼：

echo $times['monday'][2]

將回顯1-6因為數組基於0（元素從0開始）。 如果您希望3-5 ，那就是：

echo $times['monday'][1]

Answer 2

您忘記了引號，並且要初始化數組，應在括號前添加array關鍵字：

<?php
    $times['monday'] = array('7-10', '3-5', '1-6');
    $times['tuesday'] = array('5-9', '12-15', '19-22');
    echo $times['monday'][2];
?>