preg_replace：將換行符轉換爲段落

Question

我想將換行符轉換爲段落。

例如

$string = "1st paragraph 

2nd paragraph 


3rd paragraph 
"; 

我想，

<p>1st paragraph</p> 
<p>2nd paragraph</p> 
<p>3rd paragraph</p> 

，並

$string = "1st paragraph 

2nd paragraph 
a line break 

3rd paragraph 
"; 

成，

<p>1st paragraph</p> 
<p>2nd paragraph<br/>a line break</p> 
<p>3rd paragraph</p> 

regex和reg_replace可能嗎？或其他更好的東西 - xpath？

我已經試過這一點，但沒有結果呢，

echo preg_replace("'/^(.*?)(<br\s*\/?>\s*)+/'", "<p>$1</p>", nl2br($string)); 

Answer 1

做它的其他方式輪：一是通過段落取代多個換行符，然後通過<br>元素取代單換行符。

$str = preg_replace('/\n(\s*\n)+/', '</p><p>', $str); 
$str = preg_replace('/\n/', '<br>', $str); 
$str = '<p>'.$str.'</p>'; 

你也應該首先規格化行尾（windows風格到UNIX風格）：

function normalize($str) { 
    // Normalize line endings 
    // Convert all line-endings to UNIX format 
    $s = str_replace("\r\n", "\n", $s); 
    $s = str_replace("\r", "\n", $s); 
    // Don't allow out-of-control blank lines 
    $s = preg_replace("/\n{2,}/", "\n\n", $s); 
    return $s; 
} 

Answer 2

又一解決方案：

$string = preg_replace('/\n{2,}/', "</p><p>", trim($string)); 
$string = preg_replace('/\n/', '<br>',$string); 
$string = "<p>{$string}</p>";