Drupal

Drupal 8 use its own jquery version by default and if you want to use the other version of jQuery instead of default than this tutorials steps is for you, sometimes we need different version to other plugins and libraries to work if you are using external libraries or something like that . Follow the steps 

1) we need to create the "libraries-override"  attribute in yourtheme.info.yml

libraries-override:
  core/jquery: yourtheme/jquery-custom

2) Second download and placed your js file in theme folder like example:

Drupal Views

Import and Export configuration is the basic protocol to staging the website or production website deployment, In Drupal 7, we need the extra modules to import and export or we can use features modules to do so.

But In the drupal 8 that settings / configuration can we imported directly from the core system, Drupal 8 provide the system in core functionality, if you want to do this kind of stuff, please follow this tutorial.

In this tutorial we can see how to import and export a view, you can do full configuration also, so lets start

function HOOK_preprocess_page(&$vars) {
global $user;
  if (!in_array('administrator', $user->roles) && variable_get('maintenance_mode') == 1 && arg(0) != 'user') {
    $vars['theme_hook_suggestions'][] = 'maintenance_page';
  }
  else if (drupal_is_front_page()) {
    $vars['theme_hook_suggestions'][] = 'page__front';
  }
}

Drupal provided the lots of hook to extents its functionality, using this we can prevent a js file to load on particular page using HOOK_JS_ALTER

If you want to load a js on every page except some page, below example will help you to achieving this.

See Details Here

https://www.drupal.org/node/1179668

What's new?

I’ll list some changes with the theming system of Drupal 8 compared to Drupal 7. You may have got familiar with these in the Drupal 7 version. The bases are still remained, but they have changed in a new form. There may be some points you don’t understand, but don’t worry. I’ll explain them later. Now just take these as bullet points to remember.

Schema  Api Drupal 7 and Drupal 8 not accept the datatypes Like data or datatime and generate the warning and sql syntax error while installing the drupal module in install 

normally we Define like this:

'dob' => array(
		  'description' => 'Date of Birth',
		  'type' => 'date',
		  'not null' => FALSE,
		),

See the dob datatype below the correct version of using

List of Most of File Type extension for drupal File field : 

jpg, jpeg, gif, png, txt, doc, docx, xls, xlsx, pdf, ppt, pptx, pps, ppsx, odt, ods, odp, mp3, mov, mp4, m4a, m4v, mpeg, avi, ogg, oga, ogv, weba, webp, webm, zip, tar.gz, sql, sql.gz

To Enable Drupal 8 Error Reporting, Put This code at top of sites/default/settings.php.

error_reporting(E_ALL);
ini_set('display_errors', TRUE);
ini_set('display_startup_errors', TRUE);

$config['system.logging']['error_level'] = 'verbose';

;Put this code in php.ini (C:\xampp\php\php.ini)

zend_extension=php_opcache.dll

[opcache]
; Determines if Zend OPCache is enabled
opcache.enable=1

; Determines if Zend OPCache is enabled for the CLI version of PHP
opcache.enable_cli=0

; The OPcache shared memory storage size.
opcache.memory_consumption=64

; The amount of memory for interned strings in Mbytes.
opcache.interned_strings_buffer=4

; The maximum number of keys (scripts) in the OPcache hash table.
 Only numbers between 200 and 100000 are allowed.
;opcache.max_accelerated_files=2000

; The maximum percenta