PHP 在尝试访问多维数组中的元素时出现“未定义的偏移量” [duplicate]

问：

我有以下数组：

<?php
$bridal_artists = array(
    array(
        'id' => 1,
        'name' => 'Artist 01',
        'section' => array( 'engagement', 'wedding' ),
        'featured_img' => array( 'engagement' => 0, 'wedding' => 2 ),
        'images' => array(
            array( 'artist01-01.jpg', 'Classic Anne Engagement Ring' ),
            array( 'artist01-02.jpg', 'Wonky Diamond Band, 0.09ctw diamonds' ),
            array( 'artist01-03.jpg', 'Two Row Pavé Band, 0.24ctw diamonds' ),
            array( 'artist01-04.jpg', 'Narrow Pavé Diamond Band, 0.36ctw diamonds' ),
            array( 'artist01-05.jpg', 'Leslie Engagement Ring' ),
            array( 'artist01-06.jpg', 'Four Claw Pavé Diamond Engagement Ring' ),
            array( 'artist01-07.jpg', 'Louisa Engagement Ring' ),
            array( 'artist01-08.jpg', 'Original Halo Engagement Ring' ),
            array( 'artist01-09.jpg', 'Bark Textured Solitaire Engagement Ring' ),
            array( 'artist01-10.jpg', 'Alexa Engagement Ring' ),
            array( 'artist01-11.jpg', 'Dancing Diamond Engagement Ring' ),
            array( 'artist01-12.jpg', 'Trinity Engagement Ring' ),
            array( 'artist01-13.jpg', 'Scalloped Engagement Ring' ),
            array( 'artist01-14.jpg', 'Cushion Double Halo Engagement Ring' ),
            array( 'artist01-15.jpg', 'Triple Illusion Cushion Engagement Ring' ),
            array( 'artist01-16.jpg', 'Marion Engagement Ring' ),
        ),
    ),
    array(
        'id' => 2,
        'name' => 'Artist 2',
        'section' => array( 'engagement', 'wedding' ),
        'featured_img' => array( 'engagement' => 0, 'wedding' => 2 ),
        'images' => array(
            array( 'artist02-01.jpg', 'Bamboo Damascus Steel Band' ),
            array( 'artist02-02.jpg', 'Infinity Damascus Steel Band yellow gold liner and rails' ),
            array( 'artist02-03.jpg', 'Vortex Damascus Steel Band white gold liner and rails' ),
            array( 'artist02-04.jpg', 'Wood Grain Damascus Steel Band' ),
            array( 'artist02-05.jpg', 'Hailey Engagement Ring  damascus steel and gold with 0.25ct diamond' ),
            array( 'artist02-06.jpg', 'Beech Mokume-gane Band 18k yellow gold, palladium, sterling silver' ),
            array( 'artist02-07.jpg', 'Arcturus Meteorite Band, white gold, meteorite' ),
            array( 'artist02-08.jpg', 'Arcturus Meteorite Band, yellow gold, meteorite' ),
            array( 'artist02-09.jpg', 'Sirius Meteorite Band, meteorite, white gold liner and rails' ),
            array( 'artist02-10.jpg', 'Sirius Meteorite Band, meteorite, yellow gold liner and rails' ),
        ),
    ),
    array(
        'id' => 3,
        'name' => 'Artist 3',
        'section' => array( 'wedding' ),
        'featured_img' => array( 'wedding' => 1 ),
        'images' => array(
            array( 'artist03-01.jpg', 'ACE000 Mokume-gane band, 18k yellow gold, 14k white and rose gold, sterling silver, etched finish' ),
            array( 'artist03-02.jpg', 'ACE000 Mokume-gane band, 18k yellow gold, 14k white and rose gold, sterling silver, smooth finish' ),
            array( 'artist03-03.jpg', 'ZCE000 Mokume-gane band, sterling silver, palladium, tight wood-grain etched finish' ),
            array( 'artist03-04.jpg', 'ACN000 Mokume-gane band, 18k yellow gold, 14k white and rose gold, sterling silver, smooth finish' ),
            array( 'artist03-05.jpg', 'HCN000 Mokume-gane band, 14k white and rose gold, sterling silver, smooth finish' ),
            array( 'artist03-06.jpg', 'CCE000 Mokume-gane band, 14k white gold, palladium, sterling silver, etched finish' ),
        ),
    ),
    array(
        'id' => 4,
        'name' => 'Artist 4',
        'section' => array( 'engagement', 'wedding' ),
        'featured_img' => array( 'engagement' => 4, 'wedding' => 1 ),
        'images' => array(
            array( 'artist04-01.jpg', 'Cava Engagement Ring' ),
            array( 'artist04-02.jpg', 'Cava Ch Rd Band, 0.14ctw diamonds' ),
            array( 'artist04-03.jpg', 'Iris Pavé Engagement Ring, 0.19ctw diamond sides' ),
            array( 'artist04-04.jpg', 'Perth Pavé Engagement Ring and Band, 0.24ctw diamond sides' ),
            array( 'artist04-05.jpg', 'Poppy Engagement Ring, 0.22ctw diamond sides' ),
            array( 'artist04-06.jpg', 'Poppy Pavé Band, 0.17ctw sides' ),
            array( 'artist04-07.jpg', 'Sanday Engagement Ring' ),
            array( 'artist04-08.jpg', 'Scotasay Engagement Ring, 0.55ctw diamond sides' ),
        ),
    ),
);
?>

该数组保存每个艺术家的相关数据。多维的，如上所示。我使用一个 foreach 循环来遍历所有这些循环，然后使用第二个循环来遍历主键。但是，当我尝试使用键名称时，我得到“未定义的偏移量”。我尝试了数字偏移量，这给了我“非法字符串偏移量”。

        <?php foreach ($bridal_artists as $artist): ?>
            <?php foreach ($artist as $key => $value): ?>
                <?php if($key[2][0] == $cat || $value[2][1] == $cat): ?>
                   rest of logic here
                <?php endif; ?>
            <?php endforeach; ?>
        <?php endforeach; ?>

一些附加信息：数组包含在其自己的 phtml 文件中，并在必要时包含在 phtml 文件中。我使用的是PHP 7.2.24，这是针对Magento 2站点的。如果有Magento 2特定的解决方案，那就太好了。

不确定我做错了什么以及为什么这不起作用。我知道出了什么问题，否则我不会出错。我是否错误地构建了循环？用错了钥匙？在这里切换会是一个更好的主意吗？