const firstName = 'Giorgi';
const job = 'Doctor';
const birthdayYear = 1991;
const currentDate = new Date();
const currentYear = currentDate.getFullYear()

//same results but different syntax

const giorgisInfo = "I'm " + firstName + ', a ' + (currentYear - birthdayYear) + ' year old ' + job + '!';
console.log(giorgisInfo)
//----------------
const giorgisInfoNew = `I'm ${firstName}, a ${currentYear - birthdayYear} year old ${job}!`
console.log(giorgisInfoNew)

getBoundingClientRect

let element = document.getElementById("some-id"); // for jQuery $("#some-id")[0];

let elementRect = element.getBoundingClientRect();

DOMRect

tooltipRect: DOMRect
bottom: -5
height: 20
left: 1093.5625
right: 1149.59375
top: -25
width: 56.03125
x: 1093.5625
y: -25
__proto__: DOMRect
bottom: -5   //invoked
height: 20   //invoked
left: 1093.5625   //invoked
right: (...)
top: (...)
width: (...)
x: (...)
y: (...)

multiple

[]

<input type="file" multiple="multiple" name="files[]" placeholder="Attach file"/>

.*

form-group

<div class="form-group">
    <label for="files">Attach File</label> &nbsp;
    <i id="add_new_file" class="ki ki-plus text-success pointer" title="Add New File"></i>
    <input type="file" class="form-control mb-2 {{ $errors->has('files.*') ? 'is-invalid' : '' }}" multiple="multiple" name="files[]" placeholder="Attach file"/>
    @if($errors->has('files.*'))
        <div class="invalid-feedback">
            <strong>{{ $errors->first('files.*') }}</strong>
        </div>
    @endif
</div>

public function rules()
{
    return [
        'comment' => 'sometimes|nullable|min:2|max:255',
        'files.*' => 'sometimes|nullable|mimes:pdf,docx,xlsx,pptx,rar,zip,png,jpg',
    ];
}

files

.*

textarea

input

function copy(part1, part2) {

    // Creates textarea element 
    var textarea = document.createElement('textarea');

    // Puts the text into the textarea with breaklines
    textarea.value = part1 + "\n\n" + part2

    // Adds the element to the DOM
    document.body.appendChild(textarea);

    // Selects the text that we want to copy
    textarea.select();

    // Copies the selected text clipboard
    var result = document.execCommand('copy');

    // Removes the element from the DOM because we no longer need it
    document.body.removeChild(textarea);
    return result;
}

class User extends Model {  

     protected $fillable = ['name', 'email', 'mobile'];   

     // All fields inside $fillable array can be mass-assigned  

}  

public function roles()
{
    return $this->belongsToMany(Role::class, 'model_has_roles', 'model_id', 'role_id');
}

user_id

books_chapter

id 

users

$table->foreign('book_id')->references('id')->on('books');
$table->foreign('chapter_id')->references('id')->on('texts');
$table->foreign('user_id')->references('id')->on('users');

->onDelete('cascade')

$table->foreign('book_id')->references('id')->on('books')->onDelete('cascade');
$table->foreign('chapter_id')->references('id')->on('texts')->onDelete('cascade');
$table->foreign('user_id')->references('id')->on('users')->onDelete('cascade');

@if (Auth::check())
  //show logged in content
@else
  //show logged out content
@endif

public function words()
    {
        return $this->belongsToMany('App\Word', definition_word)->withTimestamps();
    }

$table

words()

public function words($table = null)
    {
        return $this->belongsToMany('App\Word', $table)->withTimestamps();
    }

vanilla JavaScript

callback function

function

function ajax(url, methodType, callback){
    var xhr = new XMLHttpRequest();
    xhr.open(methodType, url, true);
    xhr.send();
    xhr.onreadystatechange = function(){
        if (xhr.readyState === 4 && xhr.status === 200){
            if (typeof callback === "function") {
                callback(xhr.responseText);
            }
        }
    }
}

ajax(url, 'GET', function(resp) {
    console.log(resp);
})