PHP如何根据指定ID从JSON频道数据中匹配获取对应链接？

你可以根据自己的查询频次选择下面两种实现方式：

方法1：遍历匹配（适合单次/少量查询场景） #

直接循环解码后的频道列表，匹配目标ID后返回对应链接即可，逻辑简单无额外开销：

<?php
// 原有请求结果定义保持不变
$content = <<<END_OF_STRING
[{"id":"2972","name":"MBC 1","link":"http://46.105.112.116/?watch=TR/mbc1-ar&token=RED_cexVeBNZ8mioQnjmGiYNEg==,1643770076.5266113827&t=1&s=2&p=1&c=BR&r=1351&lb=1","epg":"https://epg.cdnrdn.com/MBC1En.ae-20220201.xml","dvr":"disabled","language":"Arabic","category":"TOP 100","logo":"http://files.rednetcontent.com/chlogo/mbc1.png"},{"id":"1858","name":"MBC 2","link":"http://46.105.112.116/?watch=TN/mbc2-ar&token=RED_cexVeBNZ8mioQnjmGiYNEg==,1643770076.5266113827&t=1&s=2&p=1&c=BR&r=1351&lb=1","epg":"https://epg.cdnrdn.com/MBC2En.ae-20220201.xml","dvr":"disabled","language":"Arabic","category":"TOP 100","logo":"http://files.rednetcontent.com/chlogo/mbc2.png"},{"id":"1859","name":"MBC 3","link":"http://46.105.112.116/?watch=TN/mbc3-ar&token=RED_cexVeBNZ8mioQnjmGiYNEg==,1643770076.5266113827&t=1&s=2&p=1&c=BR&r=1351&lb=1","epg":"https://epg.cdnrdn.com/-20220201.xml","dvr":"disabled","language":"Arabic","category":"TOP 100","logo":"http://files.rednetcontent.com/chlogo/mbc3.png"}]
END_OF_STRING;

$items = json_decode($content);

/**
 * 按频道ID查找对应播放链接
 * @param array $channelList json解码后的频道对象数组
 * @param string $targetId 待查找的频道ID
 * @return string|null 匹配成功返回链接，失败返回null
 */
function getLinkByChannelId(array $channelList, string $targetId): ?string
{
    foreach ($channelList as $channel) {
        // 原数据id为字符串类型，用全等匹配避免类型转换导致的匹配错误
        if ($channel->id === $targetId) {
            return $channel->link;
        }
    }
    return null;
}

// 调用示例
$targetId = "1858";
$channelLink = getLinkByChannelId($items, $targetId);

if ($channelLink) {
    echo "ID {$targetId} 对应频道链接：" . $channelLink . PHP_EOL;
} else {
    echo "未找到ID为 {$targetId} 的频道" . PHP_EOL;
}

方法2：ID索引映射（适合多次查询场景） #

如果需要频繁根据ID查询频道信息，可以先把列表重组为以ID为键的映射表，后续查询直接按键取值，时间复杂度为O(1)，性能更高：

<?php
// 原有请求结果定义、解码逻辑保持不变
$content = <<<END_OF_STRING
[{"id":"2972","name":"MBC 1","link":"http://46.105.112.116/?watch=TR/mbc1-ar&token=RED_cexVeBNZ8mioQnjmGiYNEg==,1643770076.5266113827&t=1&s=2&p=1&c=BR&r=1351&lb=1","epg":"https://epg.cdnrdn.com/MBC1En.ae-20220201.xml","dvr":"disabled","language":"Arabic","category":"TOP 100","logo":"http://files.rednetcontent.com/chlogo/mbc1.png"},{"id":"1858","name":"MBC 2","link":"http://46.105.112.116/?watch=TN/mbc2-ar&token=RED_cexVeBNZ8mioQnjmGiYNEg==,1643770076.5266113827&t=1&s=2&p=1&c=BR&r=1351&lb=1","epg":"https://epg.cdnrdn.com/MBC2En.ae-20220201.xml","dvr":"disabled","language":"Arabic","category":"TOP 100","logo":"http://files.rednetcontent.com/chlogo/mbc2.png"},{"id":"1859","name":"MBC 3","link":"http://46.105.112.116/?watch=TN/mbc3-ar&token=RED_cexVeBNZ8mioQnjmGiYNEg==,1643770076.5266113827&t=1&s=2&p=1&c=BR&r=1351&lb=1","epg":"https://epg.cdnrdn.com/-20220201.xml","dvr":"disabled","language":"Arabic","category":"TOP 100","logo":"http://files.rednetcontent.com/chlogo/mbc3.png"}]
END_OF_STRING;

$items = json_decode($content);

// 构建ID映射表
$channelMap = [];
foreach ($items as $channel) {
    $channelMap[$channel->id] = $channel;
}

// 后续多次查询无需再循环
echo "MBC1链接：" . $channelMap["2972"]->link . PHP_EOL;
echo "MBC3链接：" . $channelMap["1859"]->link . PHP_EOL;

// 查找不存在的ID前先判断键是否存在，避免抛出错误
$nonExistentId = "9999";
if (isset($channelMap[$nonExistentId])) {
    echo $channelMap[$nonExistentId]->link;
} else {
    echo "指定ID的频道不存在" . PHP_EOL;
}

注意事项 #

如果你更习惯数组操作，可以在调用json_decode时传入第二个参数true，将返回结果转为关联数组格式，对应字段访问方式从$channel->id改为$channel['id']即可，其余逻辑完全一致。
原JSON数据中id字段为字符串类型，做匹配时不要直接用整数ID做全等判断，否则会匹配失败。

内容的提问来源于stack exchange，提问作者achraf