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Javascript setTimeout handle promise rejection [closed]

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Im currently trying to make a timeout for a function
setTimeout(() => function_name(), 10000)
This function may raise an exception or reject a promise
How do I handle a rejection in this case ?
Im unsure of what to try

Just wrap it in a try/catch
setTimeout(() => {
try {
function_name();
} catch (err) {
console.log(err);
}
}, 10000);

Promise and one strange behaviour [closed]

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I encountered a strange behavior when I defined 4 Promises which the last one is described as just rejected and when I tried to run each promise separately, the last one is fired! This will fire rejection especially when I want to run all Promises (_1 _2 _3) in Promise.all().
I wanted to use catch() for promise_2 in Promise.all([promise.catch((err)=>console.log(err))]).then(...) from handling the error happend in promise_2 without cancelling the operation of other Promises
Thx
const asyncFunction=(timer,callback)=>{
setTimeout(() => {
callback(10)
}, timer);
}
const promise_1=new Promise((resolved,reject)=>{
const date=new Date().getSeconds()
date%2===0?asyncFunction(1000,(value)=>resolved(value)):reject(new Error("hello"))
})
const promise_2=new Promise((resolved,reject)=>{
asyncFunction(2000,(value)=>resolved(value))
})
const promise_3=new Promise((resolved,reject)=>{
asyncFunction(3000,(value)=>resolved(value))
})
const promise_4=new Promise((resolved,reject)=>{
reject(new Error("i am bad"))
})
promise_1.then((value)=>console.log(value))
first in Node
C:\Program Files\nodejs\node.exe .\test.js
Process exited with code 1
Uncaught Error Error: I am bad<--------------------------what is it?this is for promise_4 ,while I didn't call it
second in V8
See here
[in V81

Javascript syntax using await Promise.all [closed]

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I am trying to understand the below code/syntax which uses await Promise.all;
How is the array getting assigned from the endpoint response ?
const getState = async (code) => {
try {
const [
{data: dataResponse},
{data: stateDistrictWiseResponse},
{data: statesDailyResponse},
{data: stateTestResponse},
{data: sourcesResponse},
{data: zonesResponse},
] = await Promise.all([
axios.get('https://example.org/data.json'),
axios.get('https://example.org/state_district_wise.json'),
axios.get('https://example.org/states_daily.json'),
axios.get('https://example.org/state_test_data.json'),
axios.get('https://example.org/sources_list.json'),
axios.get('https://example.org/zones.json'),
]);
console.log(stateTestResponse.states_tested_data);
}
}

Promise.all converts an array of promises into an array of results.
axios.get returns a promise that, when resolved, returns an object with the shape { data: <result goes here>
Your code is destructuring those objects within the returned array.

Should a Javascript function avoid reject a promise via a ternary condition? [closed]

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I saw a piece of code that looks funny to me. It feels like there are multiple things wrong here. Am I seeing a ternary here returning an error rather than a value? Shouldn't this therefore be an if-else?
const aData = await response.json();
return await new Promise((resolve, reject) => {
(aData.title === aName)
? resolve('A data was found')
: reject(new Error('Incorrect data was returned'));
});

Both resolve and reject just return the value undefined, and your callback function doesn't return anything at all. Using a ternary operator to make it a single expression is rather useless.
For clarity, you should better write
if (aData.title === aName) resolve('A data was found');
else reject(new Error('Incorrect data was returned'));
although really you shouldn't be using the new Promise constructor here at all. Just
const aData = await response.json();
if (aData.title !== aName) throw new Error('Incorrect data was returned');
else return 'A data was found';

Javascript scope in promises [closed]

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How can I access to the user object in the promises callback ?
I try to bind it with no success.
const promises = User.find(req.user._id).exec();
promises.then(function (user) {
noAccessFunction().then(function (customer) {
// HERE
user.save();
});
});

Promises are not callbacks! Mutate it as if it were a chain of values. Maybe something like this:
const promises = User.find(req.user._id).exec();
promises.then(function (user) {
return myfunction().then(function (customer) {
return user.save();
});
});
Promises can also be flattened:
const promises = User.find(req.user._id).exec();
promises.then(function (user) {
return myfunction(user);
})
.then(function (customer) {
return customer.save();
});
In any case the code above is speculation since you have not provided enough information as to what you want to happen.