After compilation, JSX expressions become regular JavaScript objects.
在編譯以后，JSX表達(dá)式變成了正常JavaScript對(duì)象。
This means that you can use JSX inside of if statements and for loops, assign it to variables, accept it as arguments, and return it from functions:
那就意味你可以在if和for的內(nèi)部使用JSX嗜湃，把它賦值給變量芬探，把它當(dāng)著參數(shù)去使用讼积，從一個(gè)函數(shù)里輸出它：
function getGreeting(user) {
? ?if (user) {
? ? ? ?return <h1>Hello, {formatName(user)}!</h1>;
? ?}
? ?return ?<h1>Hello, Stranger.</h1>
}
