ES2021 新特性(20210801)

String replaceAll() Method

WeakRef and Finalizers

Promise.any() and AggregateError

Logical Assignment Operator

let x = 1;
let y = 2;
x &&= y;
x ||= y;
x ??= y;

Underscores as Numeric Seperator

const billion = 1000_000_000;
console.log(billion); // 1000000000