React is a JavaScript library, and so it assumes you have a basic understanding of the JavaScript language. If you don't feel very confident, we recommend refreshing your JavaScript knowledge so you can follow along more easily.

React 是一個JavaScript庫，所以我們假設(shè)你有對JavaScript語言有一個基本的了解。如果你感覺不是很有信心，我們建議更新JavaScript知識，那樣能學(xué)的更簡單。

We also use some of the ES6 syntax in the examples. We try to use it sparingly because it's still relatively new, but we encourage you to get familiar with arrow functions, classes, template literals, let, and const statements. You can use Babel REPL to check what ES6 code compiles to.

我們同樣在事例中使用了ES6語法。我們會盡量謹慎使用它，畢竟ES6相對來說還是很新的。但是我們鼓勵你熟悉箭頭函數(shù)，類，模板字面量，let和const的語句。你可以使用Babel REPL檢驗ES6代碼都編譯成什么了。