箭头函数“表达式预期”语法错误

I want to transform this code:

我想要转换这段代码:

var formatQuoteAmount = function (tx) {
    return Currency.toSmallestSubunit(tx.usd, 'USD');
};
var quoteAmounts = res.transactions.map(formatQuoteAmount);

into an anonymous arrow function. I've written this:

变成一个匿名箭头函数。我写这个:

var quoteAmounts = res.transactions.map(tx => Currency.toSmallestSubunit(tx.usd, 'USD'));

I get expression expected syntax error at the arrow. I looked up the default syntax here and seems like the syntax of my code is correct. Any ideas what the problem might be?

我在箭头处得到表达式期望语法错误。我在这里查找了默认语法，看起来我代码的语法是正确的。有什么问题吗?

I have it working with this syntax:

我让它使用这种语法:

    var quoteAmounts = res.transactions.map(function (tx) {
        return Currency.toSmallestSubunit(tx.usd, 'USD')
    });

but I want to make it a one-liner, with an arrow-function.

但我想把它做成一行，带有箭头函数。

Running on node v5.3.0

运行在节点v5.3.0

3 个解决方案

#1

107

I had the error expression expected reported by Webstorm when editing a Node.js program. In this case the solution is to set the language version to a version that supports this feature.

在编辑一个节点时，我得到了Webstorm所期望的错误表达式。js程序。在这种情况下，解决方案是将语言版本设置为支持该特性的版本。

#2

The following is what i did that work for me. (1) I change the JavaScript language option to ECMAScript 6 as show in the selected answer by @Joe23

以下是我为自己所做的。(1)将JavaScript语言选项改为ECMAScript 6，如@Joe23所示

(2) I close the Webstorm project/application.

(2)我关闭Webstorm项目/应用。

(3) Navigate to the project folder and delete the .idea folder in it. I believe this is the folder webstorm generated to keep information about the project/application.

(3)导航到项目文件夹，删除其中的.idea文件夹。我认为这是webstorm生成的文件夹，用来保存关于项目/应用程序的信息。

(4) I reopen my project in webstorm and the errors are gone.

我在webstorm重新打开我的项目，错误就消失了。

#3

Your syntax is correct and Nodejs supports arrow functions, but you it's not enabled by default.

语法是正确的，Nodejs支持箭头函数，但默认情况下不启用。

You should add the "--harmony" flag when you start the node process to enable it.

在启动节点进程以启用它时，应该添加“—harmony”标志。

#1

107