core-js
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Package description
The core-js npm package is a modular standard library for JavaScript, which includes polyfills for ECMAScript features. It provides reliable polyfills to ensure that code behaves consistently across different environments, including older browsers.
Polyfilling ECMAScript features
This feature allows developers to use the latest ECMAScript features while ensuring backward compatibility with older environments that do not support these features natively.
require('core-js/stable');
// Now you can use ES6 features like Promise in environments that do not support them natively.Polyfilling Web Standards
Core-js can also polyfill web standards, allowing developers to use modern web APIs in environments that have not implemented them.
require('core-js/web');
// This includes polyfills for web standards like DOM collections (e.g., NodeList), timers, and more.Polyfilling Proposals
Developers can experiment with proposed ECMAScript features before they are finalized and adopted into the standard, ensuring forward compatibility.
require('core-js/proposals');
// This will include polyfills for ECMAScript proposals that are not yet part of the standard.Babel-polyfill is a package that provides polyfills necessary for a full ES2015+ environment. It is similar to core-js but is more tightly coupled with Babel's transpilation process.
The es6-shim package provides polyfills for ECMAScript 6 (aka ECMAScript 2015) features. It is similar to core-js but focuses specifically on ES6 features and does not cover proposals or web standards.
The polyfill-service by Financial Times is an online service that provides polyfills based on the user's browser. It is different from core-js in that it is a service rather than a package you include in your project, but it serves a similar purpose in polyfilling features.
Readme
Alternative standard library for javascript. Includes polyfills for ECMAScript 5, ECMAScript 6: Set, Map, WeakSet, WeakMap, Promise, Symbol, iterators; setImmediate, static array methods, console cap. Additional functionality: Dict, extended partial application, extended object api, Date formatting and other sugar.
npm i core-js
Browser:
<script src='core.min.js'></script>
Node.js:
require('core-js');
signature from def in module
-------------------------------------------------------------------------------------------
global -> object node global
Object
.create(proto | null, descriptors?) -> object es5 es5
.getPrototypeOf(object) -> proto | null es5 sham es5
.setPrototypeOf(target, proto | null) -> target es6 sham es6
.defineProperty(target, key, desc) -> target es5 sham es5
.defineProperties(target, descriptors) -> target es5 sham es5
.getOwnPropertyNames(object) -> array es5 sham es5
.getOwnPropertyDescriptor(object, key) -> desc es5 es5
.keys(object) -> array es5 es5
.values(object) -> array es7 dict
.entries(object) -> array es7 dict
.assign(target, ...src) -> target es6 es6
.is(a, b) -> bool es6 es6
.isObject(var) -> bool core object
.classof(var) -> string core object
.define(target, mixin) -> target core object
.make(proto | null, mixin?) -> object core object
::toString() es6 fix es6
::[_](key) -> boundFn core binding
Function
::bind(object, ...args | _) -> boundFn(...args) es5 es5
::part(...args | _) -> fn(...args) core binding
::by(object | _, ...args | _) -> boundFn(...args) core binding
::only(num, that /* = @ */) -> (fn | boundFn)(...args) core binding
Array
.isArray(var) -> bool es5 es5
.from(iterable | array-like, fn(val, index)?, that) -> array es6 es6
.of(...args) -> array es6 es6
.{...Array::} js1.6 array_statics
::slice(start?, end?) -> array es5 fix es5
::join(string = ',') -> string es5 fix es5
::indexOf(var, from?) -> int es5 es5
::lastIndexOf(var, from?) -> int es5 es5
::every(fn(val, index, @), that) -> bool es5 es5
::some(fn(val, index, @), that) -> bool es5 es5
::forEach(fn(val, index, @), that) -> void es5 es5
::map(fn(val, index, @), that) -> array es5 es5
::filter(fn(val, index, @), that) -> array es5 es5
::reduce(fn(memo, val, index, @), memo?) -> var es5 es5
::reduceRight(fn(memo, val, index, @), memo?) -> var es5 es5
::fill(var, start?, end?) -> @ es5 es5
::find(fn(val, index, @), that) -> var es6 es6
::findIndex(fn(val, index, @), that) -> int es6 es6
::values() -> iterator es6 es6_iterators
::keys() -> iterator es6 es6_iterators
::entries() -> iterator (entries) es6 es6_iterators
::@@iterator() -> iterator es6 es6_iterators
::contains(var, from?) -> bool es7 array
::turn(fn(memo, val, index, @), memo = []) -> memo core array
[new] Dict(itarable (entries) | object ?) -> dict core dict
.isDict(var) -> bool core dict
.values(object) -> iterator core dict
.keys(object) -> iterator core dict
.entries(object) -> iterator (entries) core dict
.has(object, key) -> bool core dict
.get(object, key) -> val core dict
.set(object, key, value) -> object core dict
.forEach(object, fn(val, key, @), that) -> void core dict
.map(object, fn(val, key, @), that) -> new @ core dict
.filter(object, fn(val, key, @), that) -> new @ core dict
.some(object, fn(val, key, @), that) -> bool core dict
.every(object, fn(val, key, @), that) -> bool core dict
.find(object, fn(val, key, @), that) -> val core dict
.findKey(object, fn(val, key, @), that) -> key core dict
.keyOf(object, var) -> key core dict
.contains(object, var) -> bool core dict
.reduce(object, fn(memo, val, key, @), memo?) -> var core dict
.turn(object, fn(memo, val, key, @), memo = new @) -> memo core dict
new Set(iterable?) -> set es6 es6_collections
::add(key) -> @ es6 es6_collections
::clear() -> void es6 es6_collections
::delete(key) -> bool es6 es6_collections
::forEach(fn(el, el, @), that) -> void es6 es6_collections
::has(key) -> bool es6 es6_collections
::size -> uint es6 es6_collections
::values() -> iterator es6 es6_iterators
::keys() -> iterator es6 es6_iterators
::entries() -> iterator (entries) es6 es6_iterators
::@@iterator() -> iterator es6 es6_iterators
new Map(iterable (entries) ?) -> map es6 es6_collections
::clear() -> void es6 es6_collections
::delete(key) -> bool es6 es6_collections
::forEach(fn(val, key, @), that) -> void es6 es6_collections
::get(key) -> val es6 es6_collections
::has(key) -> bool es6 es6_collections
::set(key, val) -> @ es6 es6_collections
::size -> uint es6 es6_collections
::values() -> iterator es6 es6_iterators
::keys() -> iterator es6 es6_iterators
::entries() -> iterator (entries) es6 es6_iterators
::@@iterator() -> iterator (entries) es6 es6_iterators
new WeakSet(iterable?) -> weakset es6 es6_collections
::add(key) -> @ es6 es6_collections
::clear() -> void es6 es6_collections
::delete(key) -> bool es6 es6_collections
::has(key) -> bool es6 es6_collections
new WeakMap(iterable (entries) ?) -> weakmap es6 sham es6_collections
::clear() -> void es6 sham es6_collections
::delete(key) -> bool es6 es6_collections
::get(key) -> val es6 es6_collections
::has(key) -> bool es6 es6_collections
::set(key, val) -> @ es6 es6_collections
String
::trim() -> str es5 es5
::contains(str, from?) -> bool es6 es6
::startsWith(str, from?) -> bool es6 es6
::endsWith(str, from?) -> bool es6 es6
::repeat(num) -> str es6 es6
::@@iterator() -> iterator es6 sham es6_iterators
::escapeHTML() -> str core string
::unescapeHTML() -> str core string
RegExp
.escape(str) -> str es7 regexp
Number
.EPSILON -> num es6 es6
.isFinite(num) -> bool es6 es6
.isInteger(num) -> bool es6 es6
.isNaN(num) -> bool es6 es6
.isSafeInteger(num) -> bool es6 es6
.MAX_SAFE_INTEGER -> int es6 es6
.MIN_SAFE_INTEGER -> int es6 es6
.parseFloat(str) -> num es6 es6
.parseInt(str) -> int es6 es6
::@@iterator() -> iterator core number
::times(fn(i)?, that) -> array core number
::random(lim = 0) -> num core number
::{...Math} core number
Math
.acosh(num) -> num es6 es6
.asinh(num) -> num es6 es6
.atanh(num) -> num es6 es6
.cbrt(num) -> num es6 es6
.clz32(num) -> uint es6 es6
.cosh(num) -> num es6 es6
.expm1(num) -> num es6 es6
.hypot(...args) -> num es6 es6
.imul(num, num) -> int es6 es6
.log1p(num) -> num es6 es6
.log10(num) -> num es6 es6
.log2(num) -> num es6 es6
.sign(num) -> 1 | -1 | 0 | -0 | NaN es6 es6
.sinh(num) -> num es6 es6
.tanh(num) -> num es6 es6
.trunc(num) -> num es6 es6
Date
.now() -> int es5 es5
::format(str, key?) -> str core date
::formatUTC(str, key?) -> str core date
Symbol(description?) -> symbol es6 sham es6_symbol
.for(key) -> symbol es6 es6_symbol
.keyFor(symbol) -> key es6 es6_symbol
.iterator -> symbol es6 sham es6_symbol
.toStringTag -> symbol es6 es6_symbol
.pure() -> symbol || string core es6_symbol
.set(object, key, val) -> object core es6_symbol
Reflect -> object es6 es6_symbol
.ownKeys(object) -> array es6 es6_symbol
new Promise(executor(resolve(var), reject(var))) -> promise es6 es6_promise
::then(resolved(var), rejected(var)) -> promise es6 es6_promise
::catch(rejected(var)) -> promise es6 es6_promise
.resolve(var || promise) -> promise es6 es6_promise
.reject(var) -> promise es6 es6_promise
.all(iterable) -> promise es6 es6_promise
.race(iterable) -> promise es6 es6_promise
setTimeout(fn(...args), time, ...args) -> id w3c / whatwg timers
setInterval(fn(...args), time, ...args) -> id w3c / whatwg timers
setImmediate(fn(...args), ...args) -> id w3c / whatwg immediate
clearImmediate(id) -> void w3c / whatwg immediate
console(...args) -> void core console
.{...console API} console api console
.enable() -> void core console
.disable() -> void core console
$for(iterable, entries).of(fn(value, key?), that) -> void core es6_iterators
.isIterable(var) -> bool core es6_iterators
.getIterator(iterable) -> iterator core es6_iterators
core core common
.{...global} core common
.addLocale(key, object) -> @ core date
.locale(key?) -> key core date
.noConflict() -> core core common
_ -> object core / _ common
FAQs
Standard library
The npm package core-js receives a total of 26,319,751 weekly downloads. As such, core-js popularity was classified as popular.
We found that core-js demonstrated a healthy version release cadence and project activity because the last version was released less than a year ago. It has 1 open source maintainer collaborating on the project.
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