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function is not described

clean_pre() WP 1.2.0

Deprecated in 3.4.0. It is no longer supported and can be removed in future releases. It is recommended to replace this function with the same one.

Accepts matches array from preg_replace_callback in wpautop() or a string.

Ensures that the contents of a <pre>...</pre> HTML block are not converted into paragraphs or line-breaks.

No Hooks.

Return

String. The pre block without paragraph/line-break conversion.

Usage

clean_pre( $matches );
$matches(array/string) (required)
The array or string

Code of clean pre: wp-includes/deprecated.php VER 5.1.1

<?php
function clean_pre($matches) {
	_deprecated_function( __FUNCTION__, '3.4.0' );

	if ( is_array($matches) )
		$text = $matches[1] . $matches[2] . "</pre>";
	else
		$text = $matches;

	$text = str_replace(array('<br />', '<br/>', '<br>'), array('', '', ''), $text);
	$text = str_replace('<p>', "\n", $text);
	$text = str_replace('</p>', '', $text);

	return $text;
}