How to get page id by slug wordpress theme

WordPress tutorial for, How to get page id by slug wordpress theme. First find the page id using page title or page page slug.  we given sample code here.

How to get page id by slug wordpress theme

For post title use following code:

<?php
$page = get_page_by_title( 'About' );
wp_list_pages( 'exclude=' . $page->ID );
?>

For post slug use following code:

 $page = get_page_by_path( 'your-page-slug'
echo $page->ID;

Now List the child page by post slug

if ( $page = get_page_by_path( 'your-page-slug' ) ){
  wp_list_pages( 'orderby=name&depth=1&order=DESC&show_count=0&child_of=' .$page->ID . '&title_li=' );
}