— Nullish coalescing operator '??' | База знаний IT

Теги

!DOCTYPE

a

abbr

acronym

address

applet

area

article

aside

audio

b

base

basefont

bdi

bdo

bgsound

big

body

blink

blockquote

br

button

canvas

caption

center

cite

code

col

colgroup

command

comment

data

datalist

dd

del

details

dfn

dialog

dir

div

dl

dt

em

embed

fieldset

figcaption

figure

font

footer

form

frame

frameset

h1

h2

h3

h4

h5

h6

head

header

hgroup

hr

html

i

iframe

img

input

ins

isindex

kbd

keygen

label

legend

li

link

listing

main

map

marquee

mark

menu

menuitem

meta

meter

multicol

nav

nobr

noembed

noindex

noframes

noscript

object

ol

optgroup

option

output

p

param

picture

plaintext

pre

progress

q

rp

rt

rtc

ruby

s

samp

script

section

select

small

source

spacer

span

strike

strong

style

sub

summary

sup

table

tbody

td

template

textarea

tfoot

th

thead

time

title

tr

track

tt

u

ul

var

video

wbr

xmp

Универсальные атрибуты

Атрибут accesskey

Атрибут class

Атрибут contenteditable

Атрибут contextmenu

Атрибут data-*

Атрибут dir

Атрибут draggable

Атрибут dropzone

Атрибут hidden

Атрибут id

Атрибут itemid

Атрибут itemprop

Атрибут itemref

Атрибут itemscope

Атрибут itemtype

Атрибут lang

Атрибут spellcheck

Атрибут style

Атрибут tabindex

Атрибут title

События

Событие onblur

Событие onchange

Событие onclick

Событие ondblclick

Событие onfocus

Событие onkeydown

Событие onkeypress

Событие onkeyup

Событие onload

Событие onmousedown

Событие onmousemove

Событие onmouseout

Событие onmouseover

Событие onmouseup

Событие onreset

Событие onselect

Событие onscroll

Событие onsubmit

Событие onunload

Значения

MIME-типы

Адрес

Коды языков

Названия цветов

Проценты

Скрипт

Текст

Цвет

Число

Типы элементов

Аудио и видео

Документ

Изображения

Объекты

Скрипты

Списки

Посилання

Таблицы

Текст

Формы

Фреймы

Свойства

color

font-family

background

background-image

background-color

background-attachment

margin

overflow

text-align

caption-side

border

width

visibility

vertical-align

padding

white-space

quotes

text-decoration

list-style

columns

border-left

border-right

border-top

border-bottom

border-spacing

height

animation

animation-duration

animation-timing-function

animation-delay

animation-iteration-count

animation-direction

animation-fill-mode

animation-play-state

animation-name

float

clear

border-width

border-style

border-color

background-position

background-size

background-repeat

background-origin

background-clip

box-sizing

display

column-width

column-count

content

text-decoration-line

text-decoration-style

text-decoration-color

table-layout

align-content

align-items

align-self

all

backdrop-filter

backface-visibility

background-blend-mode

background-position-y

block-size

border-bottom-color

border-bottom-left-radius

border-bottom-right-radius

border-bottom-style

border-bottom-width

border-collapse

border-image

border-left-color

border-left-style

border-left-width

border-radius

border-right-color

border-right-style

border-right-width

border-top-color

border-top-left-radius

border-top-right-radius

border-top-style

border-top-width

bottom

box-decoration-break

box-shadow

caret-color

clip

column-fill

column-gap

column-rule

column-rule-color

column-rule-style

column-rule-width

column-span

counter-increment

counter-reset

cursor

direction

empty-cells

filter

flex

flex-basis

flex-direction

flex-flow

flex-grow

flex-shrink

flex-wrap

font

hyphens

image-rendering

justify-content

left

letter-spacing

line-clamp

line-height

list-style-image

list-style-position

list-style-type

margin-bottom

margin-left

margin-right

margin-top

max-height

max-width

min-height

min-width

mix-blend-mode

object-fit

opacity

order

orphans

outline

outline-color

outline-offset

outline-style

outline-width

overflow-x

overflow-y

padding-block

padding-block-end

padding-block-start

padding-bottom

padding-inline

padding-inline-end

padding-inline-start

padding-left

padding-right

padding-top

page-break-after

page-break-before

page-break-inside

perspective

perspective-origin

place-content

pointer-events

position

resize

right

scroll-behavior

tab-size

text-align-last

text-decoration-skip-ink

text-emphasis

text-emphasis-color

text-emphasis-position

text-emphasis-style

text-indent

text-orientation

text-overflow

text-shadow

text-transform

top

transform

transform-origin

transform-style

transition

transition-delay

transition-duration

transition-property

transition-timing-function

unicode-bidi

user-select

widows

word-break

word-spacing

word-wrap

writing-mode

z-index

zoom

inline-size

min-block-size

marks

font-kerning

font-size

font-stretch

font-style

font-variant

font-weight

!important

background-position-x

Правила

@font-face

@keyframes

@media

@page

@document

@import

@supports

@viewport

@charset

Селекторы

A

#id

.class

.class1.class2

*

A B

A > B

A + B

A ~ B

[attr]

[attr='value']

[attr^='value']

[attr$='value']

[attr*='value']

[attr~='value']

[attr|='value']

Псевдоклассы

Псевдокласс :active

Псевдокласс :visited

Псевдокласс :nth-child

Псевдокласс :first-child

Псевдокласс :hover

Псевдокласс :blank

Псевдокласс :checked

Псевдокласс :default

Псевдокласс :disabled

Псевдокласс :empty

Псевдокласс :enabled

Псевдокласс :first-of-type

Псевдокласс :focus

Псевдокласс :focus-within

Псевдокласс :fullscreen

Псевдоклас :in-range

Псевдокласс :indeterminate

Псевдокласс :invalid

Псевдокласс :lang

Псевдокласс :last-child

Псевдокласс :last-of-type

Псевдокласс :link

Псевдокласс :not

Псевдокласс :nth-last-child

Псевдокласс :nth-last-of-type

Псевдокласс :nth-of-type

Псевдокласс :only-child

Псевдокласс :only-of-type

Псевдокласс :optional

Псевдокласс :out-of-range

Псевдокласс :placeholder-shown

Псевдокласс :read-only

Псевдокласс :read-write

Псевдокласс :required

Псевдокласс :target

Псевдокласс :valid

Псевдоэлементы

Псевдоэлемент ::first-letter

Псевдоэлемент ::first-line

Псевдоэлемент ::selection

Псевдоэлемент ::after

Псевдоэлемент ::before

Псевдоэлемент ::backdrop

Псевдоэлемент ::placeholder

Вендорные свойства

-ms-interpolation-mode

::-ms-browse

::-ms-check

::-ms-clear

::-ms-expand

::-ms-fill

::-ms-fill-lower

::-ms-fill-upper

::-ms-reveal

::-ms-thumb

::-ms-ticks-after

::-ms-ticks-before

::-ms-tooltip

::-ms-track

::-ms-value

Значения свойств

Цвет

Медиа-запросы

Время

Размер

Угол

Число

Фильтр

currentColor

Функции

calc()

attr()

linear-gradient()

radial-gradient()

repeating-linear-gradient()

repeating-radial-gradient()

perspective()

rotate()

rotateX()

rotateY()

rotateZ()

scale()

scaleX()

scaleY()

scaleZ()

skew()

skewX()

skewY()

translate()

translateX()

translateY()

translateZ()

Единицы

ch

cm

em

ex

in

mm

pc

pt

px

rem

vh

vmax

vmin

vw

deg

grad

rad

turn

s

ms

dpi

dpcm

dppx

CSS по категориям

Текст і шрифт

Анимация

Границы

Цвет и фон

Размеры

Форматирование

Контент

Отступы и поля

Псевдоклассы

Таблицы

Списки

Флексы

Логические

Позиционирование

Печать

@-правила

Псевдоэлементы

Формы

Анимация

Анимируемые свойства

JavaScript Reference

Array

String

Number

Math

Date

Global

RegExp

Object

Classes

Error

Boolean

Operators

Statements

JSON

Typed Array

Precedence

Window Reference

Window

History

Location

Navigator

Screen

HTML DOM Reference

Document

Element

Attributes

Events

Event Objects

HTMLCollection

Style

Web APIs

Console

Fetch

Fullscreen

Geolocation

History

MediaQueryList

Storage

Validation

Other

CSSStyleDeclaration

JS Conversion

Типы компаний

Аутсорсинг

Аутстаффинг

Продуктовые

Что такое тестирование

Quality

Quality Assurance

Quality Control

Testing

Error

Defects

Failure

Debugging

Root Causes

Объекты и цели тестирования

Requirement

Test object

Test objective

Code

Feature

Принципы тестирования

Testing shows the presence of defects

Exhaustive testing

Early testing

Defects cluster

Pesticide paradox

Testing is context dependent

Absence-of-errors is a fallacy

STLC (Fundamental test process)

Test planning

Test monitoring

Test control

Test analysis

Test design

Test implementation

Test execution

Test coverage

Test plan

Удовлетворение требований

Validation

Verification

Test levels

Component

Component testing (module/unit)

Stubs

Drivers

TDD (Test Driven Development)

BDD (Behavior Driven Development)

DDT (data-driven testing)

Integration

Integration testing

Component integration testing

System integration testing

Bottom-up testing

top-down testing

big-bang testing

System testing

Acceptance testing

User acceptance testing

Contractual acceptance testing

Operational acceptance testing

Regulatory acceptance testing

Alpha testing

Beta testing

Test types

Functional testing

Non-functional Testing

Performance testing

Impact analysis

Load testing

Stress testing

Spike testing

Endurance testing

Usability testing

Installation testing

Configuration testing

Internationalization testing

Localization testing

White box testing (glass-box)

Code coverage

Black box testing

Grey box testing

Confirmation testing (re-testing)

Regression testing

Smoke testing

Sanity testing

Maintenance Testing

Exploratory testing

Pair testing

Ad-hoc testing

Compatibility testing

Static testing

Dynamic testing

Test execution

Accessibility testing

Scalability testing

Volume testing

Black box techniques

Equivalence Partitioning (partition testing)

Boundary value analysis

Boundary Value

Decision Table

Decision table testing

State Transition Testing

Use Case Testing

Pairwise testing

White-box Test Techniques

Statement coverage

Decision coverage

Condition coverage

Multiple Condition Coverage

Experience-based Test Techniques

Error Guessing

Exploratory Testing

Checklist-based Testing

An introduction

An Introduction to JavaScript

Manuals and specifications

Code editors

Developer console

JavaScript Fundamentals

Hello, world!

Code structure

The modern mode, "use strict"

Variables

Data types

Interaction: alert, prompt, confirm

Type Conversions

Basic operators, maths

Comparisons

Conditional branching: if, '?'

Logical operators

Nullish coalescing operator '??'

Loops: while and for

The "switch" statement

Functions

Function expressions

Arrow functions, the basics

JavaScript specials

Code quality

Debugging in the browser

Coding Style

Comments

Ninja code

Automated testing with Mocha

Polyfills and transpilers

Objects: the basics

Objects

Object references and copying

Garbage collection

Object methods, "this"

Constructor, operator "new"

Optional chaining '?.'

Symbol type

Object to primitive conversion

Data types

Methods of primitives

Numbers

Strings

Arrays

Array methods

Iterables

Map and Set

WeakMap and WeakSet

Object.keys, values, entries

Destructuring assignment

Date and time

JSON methods, toJSON

Advanced working with functions

Recursion and stack

Rest parameters and spread syntax

Variable scope, closure

The old "var"

Global object

Function object, NFE

The "new Function" syntax

Scheduling: setTimeout and setInterval

Decorators and forwarding, call/apply

Function binding

Arrow functions revisited

Object properties configuration

Property flags and descriptors

Property getters and setters

Prototypes, inheritance

Prototypal inheritance

F.prototype

Native prototypes

Prototype methods, objects without __proto__

Classes

Class basic syntax

Class inheritance

Static properties and methods

Private and protected properties and methods

Extending built-in classes

Class checking: "instanceof"

Mixins

Error handling

Error handling, "try...catch"

Custom errors, extending Error

Promises, async/await

Introduction: callbacks

Promise

Promises chaining

Error handling with promises

Promise API

Promisification

Microtasks

Async/await

Generators, advanced iteration

Generators

Async iteration and generators

Modules

Modules, introduction

Export and Import

Dynamic imports

Miscellaneous

Proxy and Reflect

Eval: run a code string

Currying

Reference Type

BigInt

Unicode, String internals

Document

Browser environment, specs

DOM tree

Walking the DOM

Searching: getElement*, querySelector*

Node properties: type, tag and contents

Attributes and properties

Modifying the document

Styles and classes

Element size and scrolling

Window sizes and scrolling

Coordinates

Introduction to Events

Introduction to browser events

Bubbling and capturing

Event delegation

Browser default actions

Dispatching custom events

Forms, controls

Form properties and methods

Focusing: focus/blur

Events: change, input, cut, copy, paste

Forms: event and method submit

Document and resource loading

Page: DOMContentLoaded, load, beforeunload, unload

Scripts: async, defer

Resource loading: onload and onerror

Miscellaneous

Mutation observer

Selection and Range

Event loop: microtasks and macrotasks

Binary data, files

ArrayBuffer, binary arrays

TextDecoder and TextEncoder

Blob

File and FileReader

Network requests

Fetch

FormData

Fetch: Download progress

Fetch: Abort

Fetch: Cross-Origin Requests

Fetch API

URL objects

XMLHttpRequest

Resumable file upload

Long polling

WebSocket

Server Sent Events

Frames and windows

Popups and window methods

Cross-window communication

The clickjacking attack

Storing data in the browser

Cookies, document.cookie

LocalStorage, sessionStorage

IndexedDB

Web components

From the orbital height

Custom elements

Shadow DOM

Template element

Shadow DOM slots, composition

Shadow DOM styling

Shadow DOM and events

Animation

Bezier curve

CSS-animations

JavaScript animations

Regular expressions

Patterns and flags

Character classes

Unicode: flag "u" and class \p{...}

Anchors: string start ^ and end $

Multiline mode of anchors ^ $, flag "m"

Word boundary: \b

Escaping, special characters

Sets and ranges [...]

Quantifiers +, *, ? and {n}

Greedy and lazy quantifiers

Capturing groups

Backreferences in pattern: \N and \k<name>

Alternation (OR) |

Lookahead and lookbehind

Catastrophic backtracking

Sticky flag "y", searching at position

Methods of RegExp and String