A, es6 popular new features
1. Class
2. Modular
3. Arrow function
4. Function Default parameters
The template string
6. deconstruction assignment
7. extended operator
8. Object Properties shorthand
9. Promise
10. Let the Const
Two, es7 popular new features
1. includes()
2. The index operator (power)
Three, es8 popular new features
1. async/await
2. Object.values()
3. Object.entries()
4. String padding
The end of the function parameter list allows comma
6. Object.getOwnPropertyDescriptors()