reactjs：解析错误：await是保留字

Question

./src/App.js

Line 15: Parsing error: await is a reserved word

13 |   getWeather = async=()=>{
14 | 
15 |     const api_call = await fetch('http://api.openweathermap.org/data/2.5/weather?q=Manchester,uk&appid=${API_KEY}');
   |                      ^
16 | 
17 |     const data = await api_call.json();

How can I get rid of this error?

Answer 1

Since you're new to this language, I suggest you don't use this way. That's called arrow function .

async () => { /*...*/ };

// same to

async function () { /*...*/ };

And use it with parameter(s):

async (param_1, param_2) => { /*...*/ };

// same to

async function (param_1, param_2) { /*...*/ };

In your case, the problem may come from

// remove "=" character after "async" keyword here
async=()=> { /*...*/ }

Hope this helps!

Answer 2

As others have mentioned, you have an unnecessary = symbol. The async keyword doesn't need an = symbol after it, you might think of it as a sort of 'label' for the function. Because the function isn't correctly labelled as async , the code doesn't like there being an await keyword in the body of the function.

Here are some snippets to demonstrate the difference:

 const getWeather = async=()=>{ const api_call = await fetch('http://api.openweathermap.org/data/2.5/weather?q=Manchester,uk&appid=${API_KEY}'); const data = await api_call.json(); } 

The code above is trying to set both getWeather and async to be the function you define. Here are some more examples to demonstrate:

 const test = aNonKeyword = () => { console.log('test') } const testTwo = anotherNonKeyword = 'A Test String' var var1 = var2 = var3 = 1 console.log(test) console.log(aNonKeyword) console.log(testTwo) console.log(var1) console.log(var2) console.log(var3) 

...and here's the actual, working version:

 const getWeather = async () => { const api_call = await fetch('http://api.openweathermap.org/data/2.5/weather?q=Manchester,uk&appid=${API_KEY}'); const data = await api_call.json(); } 

Answer 3

Line 13 is trying to reassign an arrow function to the reserved variable "async". Most likely a typo, one key to remember in J's is the right to left execution.