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- What is the fulfilled value of Promise.all()?
A Promise An object An array
- What is value of the argument that is passed to the onReject()?
let onFulfill = value => {console.log(value)};
let onReject = reason => {console.log(reason)};
const promise = new Promise( (resolve, reject) => {
if (false) {
resolve('success value');
} else {
reject();
}
});
promise.then(onFulfill, onReject);
‘success value’ reason undefined
- True or False: The .then() method returns a Promise.
False True
- How many parameters does a Promise constructor take?
const example = new Promise( ? ? ? );
2 1 3
- What value is printed to the console?
const asyncHello = new Promise((resolve, reject) => {
setTimeout(resolve, 1000, 'Hello!');
});
console.log(typeof asyncHello);
Promise Object Number String
- Which one of the following is NOT a state that a Promise resolves to?
Rejected Fulfilled Undefined Pending
- What state will this promise be in after 0 seconds?
const examplePromise = () => {
return new Promise((resolve, reject) => {
if (true) {
setTimeout( () => resolve('success'), 3000);
} else {
setTimeout( () => resolve('failed'), 5000);
}
});
};
Fulfilled Rejected Pending
- What will be printed to the console after running the code provided?
let link = state => {
return new Promise(function(resolve, reject) {
if (state) {
resolve('success');
} else {
reject('error');
}
});
}
let promiseChain = link(true);
promiseChain
.then( data => {
console.log(data + " 1");
return link(true);
})
.then( data => {
console.log(data+ " 2");
return link(true);
});
Your Answer:
- Which of the executor function’s parameter is called if the asynchronous task completes successfully?
const example = new Promise( (function1, function2) => {
. . .
});
function1 function2 function1 or function2
- True or False: promise1 and promise2 both produce the same output.
const examplePromise1 = new Promise((resolve, reject) => {
reject('Uh-oh!')
});
const examplePromise2 = new Promise((resolve, reject) => {
reject('Uh-oh!')
});
const onFulfill = value => {
console.log(value)
};
const onReject = reason => {
console.log(reason)
};
const promise1 = examplePromise1.then(onFulfill, onReject);
const promise2 = examplePromise2.then(onFulfill).catch(onReject);
False True