Resolving promises involves handling asynchronous operations and obtaining their results.
Example:
let promise = new Promise((resolve, reject) => {
setTimeout(() => resolve("Resolved"), 1000);
});
promise.then(result => console.log(result)); // Output: Resolved
Creating async Function:
An async function is used to write asynchronous code in a more readable and structured way.
Example:
async function fetchData() {
let response = await fetch('https://api.example.com/data');
let data = await response.json();
return data;
}
Async Await Promises:
The async...await syntax simplifies working with promises, making asynchronous code look more like synchronous code.
Example:
async function getData() {
try {
let response = await fetch('https://api.example.com/data');
let data = await response.json();
return data;
} catch (error) {
console.error("Error:", error);
}
}
Using async await syntax:
The async...await syntax lets you pause the execution of an async function until a promise is resolved.
Example:
async function fetchData() {
let response = await fetch('https://api.example.com/data');
let data = await response.json();
return data;
}
JavaScript async…await advantage:
Async...await improves code readability by allowing sequential-style programming for asynchronous tasks.
Example:
async function processData() {
let result1 = await fetch('https://api.example.com/data1');
let result2 = await fetch('https://api.example.com/data2');
return [result1, result2];
}
Async Function Error Handling:
Async functions can use try...catch blocks for consistent error handling of asynchronous code.
Example:
async function fetchData() {
try {
let response = await fetch('https://api.example.com/data');
let data = await response.json();
return data;
} catch (error) {
console.error("Error:", error);
}
}
The async and await Keywords:
The "async" keyword is used to define a function that returns a promise. "await" is used within an async function to pause execution until the promise is resolved.
Example:
async function doSomething() {
let result = await someAsyncFunction();
return result;
}