How to Disable Theme Editor and Plugin Editor in WordPress Admin Panel

You need to do is to disable the theme editor and the Plugin Editor. To do that, open your wp-config.php file and add the following code to it:

#wp-config.php
define( 'DISALLOW_FILE_EDIT', true );
define( ‘DISALLOW_FILE_MODS’, true );

Or specific page disable following code to it :

#functions.php

function remove_menus() {
	remove_menu_page( 'index.php' );                  //Dashboard
	remove_menu_page( 'jetpack' );                    //Jetpack* 
	remove_menu_page( 'edit.php' );                   //Posts
	remove_menu_page( 'upload.php' );                 //Media
	remove_menu_page( 'edit.php?post_type=page' );    //Pages
	remove_menu_page( 'edit-comments.php' );          //Comments
	remove_menu_page( 'themes.php' );                 //Appearance
	remove_menu_page( 'plugins.php' );                //Plugins
	remove_menu_page( 'users.php' );                  //Users
	remove_menu_page( 'tools.php' );                  //Tools
	remove_menu_page( 'options-general.php' );        //Settings
}
add_action( 'admin_menu', 'remove_menus' );