Using fetch and store value in a global variable

Question

Working on my JavaScript skills I'm stuck on this bit was wondering if anyone could help please?

Objective: is to store value from request and place it in a globally accessible variable.

const CurreField = document.querySelector('#cctype');
const AmountFields = document.querySelector('#curAmount');
let data_test ="";
 

async function getValue() {
const results = await fetch("https://api.exchangeratesapi.io/latest")
const data = await results.json(); 
const value_pick = data.rates.USD
return value_pick
}



let get_data;
getValue().then(data => {
get_data = data;

});


let value_manipulate = get_data // not sure how to fix this bit

// I want to achieve a console.log(value_manipulate)

You are already making `get_data` global ..... BUT.... you can't use it until after the asynchronous promise has resolved — charlietfl, Aug 29 '20 at 17:23
This is not possible. (Or: you've done it correctly, but were accessing the global variable too early). Instead, store a promise for the result in the global variable, and then wait for it in every place you need it. — Bergi, Aug 29 '20 at 17:23
new to this javascript any idea how i would do this?@Bergi @charlietfl would you recommend a settimeout? — code_novice_1234, Aug 29 '20 at 17:30
@charlietfl so you recommend doing all my logic in the then instead of working with a global variable? or anything outside the code? — code_novice_1234, Aug 29 '20 at 17:36
In general...yes. Doesn't mean you can't store the data global for later access but depends what you are doing in the app. If you only need that data once consume it in the then() — charlietfl, Aug 29 '20 at 17:37
Cheers @charlietfl for future use what would you recommend if i wish to use it at a later stage? — code_novice_1234, Aug 29 '20 at 17:39
@charlietfl how can i use and store the data in a global variable which i can use later on? — code_novice_1234, Aug 29 '20 at 17:43
You are already storing it in variable named get_data. Important to understand that the request takes time to go to server and back and other code doesn't stop while that happens. That's why promise is used to return something in the future — charlietfl, Aug 29 '20 at 17:45
@charlietfl yes i agree but the data doesn't come back. it comes as undefined. — code_novice_1234, Aug 29 '20 at 17:47
nope, let get_data; getValue().then(data => { }); console.log(get_data) — code_novice_1234, Aug 29 '20 at 17:48
But I just explained ( as does the duplicate link) that you need to consume it inside the then(). You are trying to eat a pizza before it gets delivered when you log it outside then() — charlietfl, Aug 29 '20 at 17:49
so its not possible to store it outside in a global variable.. and to echo your point its best to work in the then. so how is this possible "Doesn't mean you can't store the data global for later access" — code_novice_1234, Aug 29 '20 at 17:52
Later means when needed after user a event for example. Not later in the immediate sequence of the code getting it — charlietfl, Aug 29 '20 at 17:55
@charlietfl ah i see now thanks for the clarification and your time :) — code_novice_1234, Aug 29 '20 at 18:02

Using fetch and store value in a global variable

0 Answers0