ES6 (ECMAScript 2015) introduced many new features and syntax, some of which may be relatively obscure, but very practical. This article will introduce some of these advanced tips, including
- Object.entries()
- Object.fromEntries()
- Symbol type and Symbol properties
- WeakMap and WeakSet
- Promise.allSettled()
- BigInt
- Array.of
- Array.from
- .at和flat
1.Object.entries() and Object.fromEntries()
- Object.entries() method returns an array of key-value pairs of a given object’s own enumerable properties.
- Object.fromEntries() method converts a list of key-value pairs into an object.
When using Object.entries(), you can pass in an object as a parameter. This object can be any object that has enumerable properties. For example:
const obj = { a: 1, b: 2, c: 3 };
const entries = Object.entries(obj);
console.log(entries); // [["a", 1], ["b", 2], ["c", 3]]In this example, we pass an object that contains three properties to the Object.entries() method and store the returned result in the entries variable. The entries variable is now an…
