php正则preg_replace_callback函数用法实例

发布:smiling　来源: PHP粉丝网　添加日期：2021-05-27 14:12:23　浏览: 评论：0　

这篇文章主要介绍了php正则preg_replace_callback函数用法,实例分析了preg_replace_callback函数进行正则替换的相关技巧,需要的朋友可以参考下

本文实例讲述了php正则preg_replace_callback函数的用法，分享给大家供大家参考，具体实现方法如下：

php正则表达式功能强大，本范例演示了preg_replace_callback函数的用法

// Define a dummy text, for testing...

$Text = "Title: Hello world!\n";

$Text .= "Author: Jonas\n";

$Text .= "This is a example message!\n\n";

$Text .= "Title: Entry 2\n";

$Text .= "Author: Sonja\n";

$Text .= "Hello world, what's up!\n";

// This function will replace specific matches

// into a new form

function RewriteText($Match){

  // Entire matched section:

  // --> /.../

  $EntireSection = $Match[0];

  // --> "\nTitle: Hello world!"

  // Key

  // --> ([a-z0-9]+)

  $Key      = $Match[1];

  // --> "Title"

  // Value

  // --> ([^\n\r]+)

  $Value    = $Match[2];

  // --> "Hello world!"

  // Add some bold (<b>) tags to around the key to

  return '<b>' . $Key . '</b>: ' . $Value;

}

// The regular expression will extract and pass all "key: value" pairs to

// the "RewriteText" function that is definied above

$NewText = preg_replace_callback('/[\r\n]([a-z0-9]+): ([^\n\r]+)/i', "RewriteText", $Text);

// Print the new modified text

print $NewText;