PHP代码问题：无符合条件作者时如何返回默认ID？

现有一段PHP代码，可返回文章文本中出现次数超过一次的作者ID，运行正常。现需优化代码，使其在没有作者符合该条件时返回默认ID。以下是原始正常代码及添加else后失效的尝试代码：

原始正常代码 #

<?php
$article = "This is a article is written by the three authors - Smith, Jackson, Peters. Peterson is not author. The main author of the article is Jackson.";

$authors = [1=>'Smith', 2=>'Jackson', 3=>'Peters'];

foreach ($authors as $id=>$author) {
    preg_match_all('/\b'.$author.'\b/', $article, $match);
    if (count($match[0])>1) {
        return $id; 
    }
}
?>

失效的尝试代码 #

<?php
$article = "This is a article is written by the three authors - Smith, Jackson, Peters. Peterson is not author. The main author of the article is Jackson.";

$authors = [1=>'Smith', 2=>'Phillips', 3=>'Peters'];

foreach ($authors as $id=>$author) {
    preg_match_all('/\b'.$author.'\b/', $article, $match);
    if (count($match[0])>1) {
        return $id;
    }
    else {
        return '1899';
    }
}
?>

问题分析 #

尝试代码失效的核心原因是：循环第一次执行时，只要当前作者不满足出现次数>1的条件，就会触发else分支里的return语句，直接终止循环并返回默认ID，根本没机会检查后续的作者。

解决方案 #

正确的逻辑是先遍历完所有作者，确认没有符合条件的后再返回默认ID。可以先初始化一个默认值，遍历过程中找到符合条件的作者就更新这个值，遍历结束后返回最终结果：

<?php
$article = "This is a article is written by the three authors - Smith, Jackson, Peters. Peterson is not author. The main author of the article is Jackson.";

$authors = [1=>'Smith', 2=>'Phillips', 3=>'Peters'];
$defaultId = '1899';
$resultId = $defaultId;

foreach ($authors as $id=>$author) {
    preg_match_all('/\b'.$author.'\b/', $article, $match);
    if (count($match[0])>1) {
        $resultId = $id;
        // 如果只需要返回第一个符合条件的作者，这里可以直接break跳出循环
        break;
    }
}

return $resultId;
?>

如果需要返回所有出现次数超过一次的作者ID，可以把结果改成数组形式：

<?php
$article = "This is a article is written by the three authors - Smith, Jackson, Peters. Peterson is not author. The main author of the article is Jackson. Smith also contributed to this article.";

$authors = [1=>'Smith', 2=>'Jackson', 3=>'Peters'];
$defaultId = '1899';
$resultIds = [];

foreach ($authors as $id=>$author) {
    preg_match_all('/\b'.$author.'\b/', $article, $match);
    if (count($match[0])>1) {
        $resultIds[] = $id;
    }
}

// 如果没有符合条件的作者，返回默认ID；否则返回所有符合条件的ID数组
return empty($resultIds) ? $defaultId : $resultIds;
?>

内容的提问来源于stack exchange，提问作者Boris Smolyanov