问题：
When returning an object from an arrow function, it seems that it is necessary to use an extra set of {} and a return keyword because of an ambiguity in the grammar. 从箭头函数返回对象时，由于语法上的歧义，似乎有必要使用额外的{}和return关键字。
That means I can't write p => {foo: "bar"} , but have to write p => { return {foo: "bar"}; } 这意味着我不能写p => {foo: "bar"} ，而必须写p => { return {foo: "bar"}; } p => { return {foo: "bar"}; } . p => { return {foo: "bar"}; } 。
If the arrow function returns anything other than an object, the {} and return are unnecessary, eg: p => "foo" . 如果arrow函数返回的不是对象，则{}和return都是不必要的，例如： p => "foo" 。
p => {foo: "bar"} returns undefined . p => {foo: "bar"}返回undefined 。
A modified p => {"foo": "bar"} throws “ SyntaxError : unexpected token: ' : '” . 修改后的p => {"foo": "bar"}抛出“ SyntaxError ：意外令牌：' : '” 。
Is there something obvious I am missing? 有什么明显的我想念的东西吗？
解决方案：
参考一： https://stackoom.com/question/1wiUx/返回对象的ECMAScript-箭头函数参考二： https://oldbug.net/q/1wiUx/ECMAScript-6-arrow-function-that-returns-an-object
来源：oschina
链接：https://my.oschina.net/u/3797416/blog/4406260