JS Built-ins

JavaScript Practice

Master the Standard Built-in Objects

2426+ interactive TypeScript exercises for every constructor, static method, instance method, and property — inspired by Codewars and Codility.

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JavaScript Learning Path
Structured roadmap from fundamentals to advanced
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Built-in Objects (65)

Array

0/226

String

0/195

Object

0/150

Number

0/105

Math

0/215

Date

0/120

RegExp

0/45

Map

0/55

Set

0/85

Symbol

0/40

JSON

0/10

Boolean

0/15

Error

0/25

BigInt

0/25

WeakMap

0/25

WeakSet

0/20

Promise

0/30

Function

0/80

Proxy

0/100

Reflect

0/140

Generator

0/25

Iterator

0/20

ArrayBuffer

0/5

DataView

0/5

GlobalFunctions

0/40

WeakRef

0/10

FinalizationRegistry

0/10

Intl

0/25

Atomics

0/5

TypedArray

0/25

globalThis

0/5

structuredClone

0/5

TypeError

0/5

RangeError

0/5

SyntaxError

0/5

ReferenceError

0/5

AggregateError

0/5

SharedArrayBuffer

0/5

URL

0/20

URLSearchParams

0/25

TextEncoder

0/10

TextDecoder

0/10

Blob

0/15

File

0/5

FormData

0/15

AbortController

0/10

AbortSignal

0/5

EventTarget

0/10

Event

0/15

performance

0/10

console

0/10

crypto

0/10

Closures

0/20

FunctionalProgramming

0/25

Prototypes

0/20

AsyncPatterns

0/20

DesignPatterns

0/25

Algorithms

0/25

TypeScript

0/100

Variables

0/10

Operators

0/13

ControlFlow

0/13

TypeCoercion

0/10

StrictMode

0/6

Modules

0/9

Redux Architecture Examples

Página 01

Redux legacy

Action types, action creators, reducer manual y legacy_createStore.

Página 02

Redux Toolkit

configureStore, slice, selectors memoizados y thunk.

Comparación

Redux Comparison

Side-by-side visualización con state, timeline y DevTools sync mode.