Javascript's () => syntax

Question

I just learned javascript and node.js. When I was studying an example, I found the following writing method, but webstorm directly marked the error and displayed expression expected. What is going on?

'use strict';

const fs = require('fs');

console.log('script start');    

const interval = setInterval(() => {
        console.log('setInterval')
}, 500);

Answer 1

() => {}This is the arrow function of ES6. Set webstorm to support ES6.

Answer 2

Change the configuration. I am using PhpStrom, but it should be similar.

Answer 3

=>Arrow function, introduced here:
Arrow function

Switch on webstorm中需要打开ES6:

Settings -> Language & Framework -> JavaScript -> Set the right side to ECMAScript6

Answer 4

Lambda expression is only supported by es6