JavaScript Global Objects

29 in total

Global objects are JavaScript's built-in toolkit - Array, String, Object, Math, JSON, Promise and more. Each one bundles related methods and properties you can use anywhere without importing a thing. Here are all 29, each with its key members and live examples.

Name	Description
AbortController	Lets you cancel async operations like fetch requests, event listeners and timers via a signal.
Array	The built-in object for ordered lists of values, with dozens of methods for transforming them.
BigInt	A primitive type for integers larger than Number can safely represent.
Boolean	The true/false type, plus the rules of truthy and falsy values that drive conditions.
Date	The built-in object for working with dates and times: creating, reading and formatting them.
Error	The object that represents a runtime error, carrying a message and a stack trace.
FormData	Collects form field values into an object you can read or send, including file uploads.
globalThis	A standard reference to the global object that works in browsers, Node and workers alike.
IntersectionObserver	Efficiently watches when elements enter or leave the viewport, for lazy loading and scroll effects.
Intl.DateTimeFormat	Formats dates and times for a locale, with control over which parts to show.
Intl.NumberFormat	Formats numbers, currency and percentages for a locale, with separators and symbols.
JSON	A built-in namespace for converting between JavaScript values and JSON text with stringify and parse.
localStorage	Browser storage that keeps string key-value data on the user's device, even after the page closes.
Map	A key-value collection that allows any type of key and remembers insertion order.
Math	A built-in namespace of mathematical constants and functions like random, round, floor and max.
MutationObserver	Watches an element for DOM changes: added or removed nodes, attribute and text changes.
Number	The built-in for numeric values, with helpers for parsing, formatting and validating numbers.
Object	The built-in for key-value collections, plus static helpers like Object.keys and Object.assign.
Promise	An object representing the eventual result of an asynchronous operation: pending, fulfilled or rejected.
Proxy	Wraps an object to intercept and customize operations like reading, writing and deleting properties.
Reflect	A built-in object with methods that perform the default operations on objects, designed to pair with Proxy.
RegExp	A pattern for matching text, used to search, validate, extract and replace strings.
sessionStorage	Browser storage that keeps string key-value data only for the current tab session.
Set	A collection of unique values: duplicates are automatically ignored.
String	The built-in object for text, with methods for searching, slicing and transforming strings.
Symbol	A primitive that creates a unique, collision-proof identifier, often used as an object key.
URLSearchParams	A helper for reading and building URL query strings without manual string parsing.
WeakMap	A Map whose keys must be objects and are held weakly, so they can be garbage collected.
WeakSet	A Set whose values must be objects and are held weakly, so they can be garbage collected.

References