The formatted output of a list of pages.

Displays page links for paginated posts (i.e. includes the <!–nextpage–>. Quicktag one or more times). This tag must be within The Loop.

Signature

wp_link_pages( $args = '' )
args
 (string|array) Optional. Array or string of default arguments.
Default: ''

Return

(string) Formatted output in HTML.

Source

function wp_link_pages( $args = '' ) {
	$defaults = array(
		'before'           => '<p>' . __( 'Pages:' ),
		'after'            => '</p>',
		'link_before'      => '',
		'link_after'       => '',
		'next_or_number'   => 'number',
		'separator'        => ' ',
		'nextpagelink'     => __( 'Next page' ),
		'previouspagelink' => __( 'Previous page' ),
		'pagelink'         => '%',
		'echo'             => 1
	);

	$params = wp_parse_args( $args, $defaults );

	/**
	 * Filter the arguments used in retrieving page links for paginated posts.
	 *
	 * @since 3.0.0
65 more lines...
WP Trac GitHub

Link here