PHP实现从指定单词开始删除后续全部字符串的技术问询

下面提供两种实用实现方式，适配你的需求场景：

方法一：字符串定位截取（基础版） #

通过定位目标单词的起始位置，截取该位置之前的内容，适合纯文本或简单HTML场景：

$originalText = 'Lorem Ipsum is simply the dummy text of printers and text files. Lorem Ipsum has been the industry\'s standard dummy text since the 1500s, when an <strong>unknown</strong> printer used a gallery of type and mixed it up in such a way that he managed to make a specimen textbook. Not only did it survive 500 years, but it also entered as a text of';
$targetWord = 'unknown';

// 查找目标单词的首次出现位置
$pos = strpos($originalText, $targetWord);
// 若找到则截取前面的内容，否则返回原文本
$result = $pos !== false ? substr($originalText, 0, $pos) : $originalText;

// 可选：清理末尾残留的未闭合HTML标签（适配你的示例需求）
$result = preg_replace('/<[^>]*$/', '', $result);

echo $result;

方法二：正则表达式替换（灵活版） #

适合需要更精准匹配的场景（如忽略大小写、匹配完整单词），直接替换目标单词及后续所有内容：

$originalText = 'Lorem Ipsum is simply the dummy text of printers and text files. Lorem Ipsum has been the industry\'s standard dummy text since the 1500s, when an <strong>unknown</strong> printer used a gallery of type and mixed it up in such a way that he managed to make a specimen textbook. Not only did it survive 500 years, but it also entered as a text of';
$targetWord = 'unknown';

// 转义目标单词的特殊字符，避免正则语法冲突
$safeWord = preg_quote($targetWord, '/');
// 匹配从目标单词到文本末尾的所有内容并替换为空
$result = preg_replace("/{$safeWord}.*/s", '', $originalText);

// 可选：清理末尾残留的未闭合HTML标签
$result = preg_replace('/<[^>]*$/', '', $result);

echo $result;

两种方法最终输出结果均为：

Lorem Ipsum is simply the dummy text of printers and text files. Lorem Ipsum has been the industry's standard dummy text since the 1500s, when an

内容的提问来源于stack exchange，提问作者Kezman10