how to get plugin directory path in wordpress code example

Example 1: how to get plugin directory path in wordpress

//current path: /home/user/var/www/wordpress/wp-content/plugins/my-plugin/
$dir = plugin_dir_path( __DIR__ );
//$dir is set to /home/user/var/www/wordpress/wp-content/plugins/

Example 2: how to get plugin directory path in wordpress

if ( is_admin() ) {
    include_once( plugin_dir_path( __FILE__ ) . 'includes/admin-functions.php' );
} else {
    include_once( plugin_dir_path( __FILE__ ) . 'includes/front-end-functions.php' );
}

Example 3: how to get plugin directory path in wordpress

function enqueue_scripts() {
    wp_enqueue_script( 'custom-js', plugin_dir_url( __FILE__ ) . 'js/custom.js', array( 'jquery' ), '', true );
    wp_enqueue_style( 'style-css', plugin_dir_url( __FILE__ ) . 'css/style.css' );
}
add_action( 'wp_enqueue_scripts', 'enqueue_scripts');
 
function admin_enqueue_scripts() {
    wp_enqueue_script( 'custom-js', plugin_dir_url( __FILE__ ) . 'js/custom.js', array( 'jquery' ), '', true );
    wp_enqueue_style( 'style-css', plugin_dir_url( __FILE__ ) . 'css/style.css' );
}
add_action( 'admin_enqueue_scripts', 'admin_enqueue_scripts');

Example 4: how to get plugin directory path in wordpress

$dir = plugin_dir_path( __FILE__ );
// Example: /home/user/var/www/wordpress/wp-content/plugins/my-plugin/

Example 5: how to get plugin directory path in wordpress

define( 'MY_PLUGIN_PATH', plugin_dir_path( __FILE__ ) );
include( MY_PLUGIN_PATH . 'includes/admin-page.php');
include( MY_PLUGIN_PATH . 'includes/classes.php');
// etc.

Example 6: how to get plugin directory path in wordpress

foreach ( glob( plugin_dir_path( __FILE__ ) . "subfolder/*.php" ) as $file ) {
    include_once $file;
}

Example 7: how to get plugin directory path in wordpress

/**
 * Include CSS file for MyPlugin.
 */
function myplugin_scripts() {
    wp_register_style( 'foo-styles',  plugin_dir_url( __FILE__ ) . 'assets/foo-styles.css' );
    wp_enqueue_style( 'foo-styles' );
}
add_action( 'wp_enqueue_scripts', 'myplugin_scripts' );

Answer
http://example.com/wp-content/plugins/my-plugin/assets/foo-styles.css

Example 8: how to get plugin directory path in wordpress

function plugin_dir_path( $file ) {
    return trailingslashit( dirname( $file ) );
}