{"id":8602,"date":"2025-02-23T11:00:39","date_gmt":"2025-02-23T05:30:39","guid":{"rendered":"https:\/\/pheonixsolutions.com\/blog\/?p=8602"},"modified":"2025-02-23T11:00:43","modified_gmt":"2025-02-23T05:30:43","slug":"async-await","status":"publish","type":"post","link":"https:\/\/pheonixsolutions.com\/blog\/async-await\/","title":{"rendered":"Async\/Await"},"content":{"rendered":"\n

The async\/await syntax is a special syntax created to help you work with promise objects. It makes your code cleaner and clearer.<\/p>\n\n\n\n

When handling Promise, we need to chain the call to the function or variable that returns a\u00a0Promise using\u00a0then\/catch methods.<\/p>\n\n\n\n

Async Keyword<\/h2>\n\n\n\n

We use the\u00a0async keyword with a function to represent that the function is an asynchronous function. The async function returns a promise.<\/p>\n\n\n\n

async function name(parameter1, parameter2, \u2026paramaterN) {
\/\/ statements
}<\/p>\n\n\n\n

\"\"<\/a><\/figure>\n\n\n\n

In this snippet the\u00a0async\u00a0keyword is used before the function to represent that the function is asynchronous.<\/p>\n\n\n\n

Since this function returns a promise, we can use the chaining method\u00a0then()<\/code>.<\/p>\n\n\n\n

\"\"<\/a><\/figure>\n\n\n\n

In this snippet f()<\/code>\u00a0function is resolved and the\u00a0then()<\/code>\u00a0method gets executed.<\/p>\n\n\n\n

Await Keyword<\/h2>\n\n\n\n

The\u00a0await keyword is used inside the\u00a0async\u00a0function to wait for the asynchronous operation. <\/p>\n\n\n\n

let result = await promise<\/p>\n\n\n\n

The use of\u00a0await\u00a0pauses the async function until the promise returns a result (resolve or reject) value. <\/p>\n\n\n\n

\"\"<\/a><\/figure>\n\n\n\n

In this snipper a\u00a0Promise\u00a0object is created and it gets resolved after 4000 milliseconds. Here, the\u00a0asyncFunc()<\/code>\u00a0function is written using the\u00a0async\u00a0function. The\u00a0await\u00a0keyword waits for the promise to be complete (resolve or reject).<\/p>\n\n\n\n

Hence,\u00a0hello\u00a0is displayed only after promise value is available to the\u00a0result\u00a0variable. If\u00a0await<\/code>\u00a0is not used,\u00a0hello\u00a0is displayed before\u00a0Promise resolved.<\/p>\n\n\n\n

Error Handling<\/h2>\n\n\n\n

While using the\u00a0async<\/code>\u00a0function, we write the code in a synchronous manner. And you can also use the\u00a0catch()<\/code>\u00a0method to catch the error.\u00a0<\/p>\n\n\n\n

\"\"<\/a><\/figure>\n\n\n\n

In this snippet try\/catch\u00a0block to handle the errors. If the program runs successfully, it will go to the\u00a0try\u00a0block. And if the program throws an error, it will go to the\u00a0catch\u00a0block.<\/p>\n\n\n\n

Promise vs Async\/Await Code Comparison<\/h2>\n\n\n\n

In the async\/await version, the result of the promise is directly assigned to a variable. In the standard promise version, the result of the promise is passed as an argument to the\u00a0.then()\u00a0method.<\/p>\n\n\n\n

Most of them prefer the async\/await version as it looks more straightforward.<\/p>\n\n\n\n

\"\"<\/a><\/figure>\n\n\n\n

How to Use Async\/Await in IIFE and Arrow Functions<\/h2>\n\n\n\n

An Immediately Invoked Function Expression (IIFE) is a technique used to execute a function immediately as soon as you define it.Unlike regular functions and variables, IIFEs will be removed from the running process once they are executed.<\/p>\n\n\n\n

Aside from the standard function, we can also make an asynchronous IIFE. This is useful when we need to run the asynchronous function only once.<\/p>\n\n\n\n

(async function () {
try {
const response = await fetch(‘https:\/\/jsonplaceholder.typicode.com\/todos\/1’);
const json = await response.json();
console.log(json);
} catch (error) {
console.log(error);
}
})();<\/p>\n\n\n\n

\u00a0Arrow syntax when creating an asynchronous function<\/strong><\/p>\n\n\n\n

const runProcess = async () => {
try {
const response = await fetch(‘https:\/\/jsonplaceholder.typicode.com\/todos\/1’);
const json = await response.json();
console.log(json);
} catch (error) {
console.log(error);
}
};<\/p>\n\n\n\n

runProcess();<\/p>\n\n\n\n

Benefits of Using async Function<\/h2>\n\n\n\n