PHP function nl2br() and custom function nl2p() line break usage analysis_php skills

The example in this article describes the use of PHP function nl2br() and custom function nl2p() to wrap. Share it with everyone for your reference, the details are as follows:

Usage scenarios

In many cases, we simply use textarea to obtain long input from users without using an editor. Line breaks for user input end with " " into the library, sometimes there will be no line breaks when outputting, and a large piece of text will come out directly. At this time, you can use the " "Wrap text. PHP has its own function nl2br(), and we can also customize the function nl2p().

Let’s take a look at the nl2br() function first.

Definition and usage

The

nl2br() function inserts an HTML newline character (
) before each new line (n) in a string.

A simple example:

<&#63;php
$str = "Welcome to 
www.jb51.net";
echo nl2br($str);
&#63;>

HTML code of running results:

Welcome to <br />
www.jb51.net

nl2p

nl2br has a shortcoming. For example, it is more troublesome to use CSS to indent paragraphs. In this case, nl2p is needed. Replace br line break with paragraph p line break. It is easier to replace it directly:

<&#63;php
function nl2p($text) {
 return "<p>" . str_replace("\n", "</p><p>", $text) . "</p>";
}
&#63;>

For more detailed functions, you can try:

/**
 * Returns string with newline formatting converted into HTML paragraphs.
 *
 * @param string $string String to be formatted.
 * @param boolean $line_breaks When true, single-line line-breaks will be converted to HTML break tags.
 * @param boolean $xml When true, an XML self-closing tag will be applied to break tags (<br />).
 * @return string
 */
function nl2p($string, $line_breaks = true, $xml = true)
{
  // Remove existing HTML formatting to avoid double-wrapping things
  $string = str_replace(array('<p>', '</p>', '<br>', '<br />'), '', $string);
  // It is conceivable that people might still want single line-breaks
  // without breaking into a new paragraph.
  if ($line_breaks == true)
    return '<p>'.preg_replace(array("/([\n]{2,})/i", "/([^>])\n([^<])/i"), array("</p>\n<p>", '<br'.($xml == true &#63; ' /' : '').'>'), trim($string)).'</p>';
  else 
    return '<p>'.preg_replace("/([\n]{1,})/i", "</p>\n<p>", trim($string)).'</p>';
}

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I hope this article will be helpful to everyone in PHP programming.