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function is not described

get_page_link() WP 1.5.0

Retrieves the permalink for the current page or page ID.

Respects page_on_front. Use this one.

Hooks in function
Return

String. The page permalink.

Usage

get_page_link( $post, $leavename, $sample );
$post(int/WP_Post)
Post ID or object.
Default: uses the global $post
$leavename(true/false)
Whether to keep the page name.
Default: false
$sample(true/false)
Whether it should be treated as a sample permalink.
Default: false

Code of get page link: wp-includes/link-template.php VER 5.0.3

<?php
function get_page_link( $post = false, $leavename = false, $sample = false ) {
	$post = get_post( $post );

	if ( 'page' == get_option( 'show_on_front' ) && $post->ID == get_option( 'page_on_front' ) )
		$link = home_url('/');
	else
		$link = _get_page_link( $post, $leavename, $sample );

	/**
	 * Filters the permalink for a page.
	 *
	 * @since 1.5.0
	 *
	 * @param string $link    The page's permalink.
	 * @param int    $post_id The ID of the page.
	 * @param bool   $sample  Is it a sample permalink.
	 */
	return apply_filters( 'page_link', $link, $post->ID, $sample );
}