用php替换段落中的特定文本模式

Question

我需要使用 preg_replace 或其他方式替换以“标题：”开头并以“文章正文：”结尾的文本。被替换的文本不会包含上面引用的单词。

例如：

标题：

示例文本 1

文章正文：

示例文本 2

应该只输出

示例文本 2

我怎样才能用 php 做到这一点？

Answer 1

使用正/负前瞻。

$result = preg_replace('/(?<=Title:).*(?=Article Body:)/s', '\nTest\n', $subject);

上面的正则表达式将替换 Title: ... Article Body: 中的任何内容 \nTest\n

解释：

"
(?<=                # Assert that the regex below can be matched, with the match ending at this position (positive lookbehind)
   Title:              # Match the characters “Title:” literally
)
.                   # Match any single character
   *                   # Between zero and unlimited times, as many times as possible, giving back as needed (greedy)
(?=                 # Assert that the regex below can be matched, starting at this position (positive lookahead)
   Article\ Body:      # Match the characters “Article Body:” literally
)
"

Answer 2

$str = 'Title: this is sample text Article Body: this is also sample text';

// output: this is sample text this is also sample text
echo preg_replace('~Title: (.*)Article Body: (.*)~', '$1 $2', $str);

正则表达式非常有用，你应该学会如何使用它。网上有很多文章，还有这个summarize 可以帮你。