php正则preg_replace_callback函数用法实例

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;

希望本文所述对大家的php程序设计有所帮助。