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Practice

Async/Await Handling Asynchronous Processes

async and await are syntactic features in JavaScript that help manage asynchronous processes in a straightforward and clean manner.

When using Promises, repeatedly chaining callbacks with .then() and .catch() can make the code complex and difficult to read.

async/await resolves this issue, allowing you to write asynchronous code that resembles synchronous code.

This type of asynchronous handling is typically used when retrieving data from external servers or storage, as these tasks can be time-consuming.

For reference, interfaces used when fetching or sending data to servers are known as APIs.

API stands for Application Programming Interface, denoting the set of rules for server communication.


async/await Example
async function fetchUserData() {
  try {
    // Using the fetch function to retrieve data from an external API
    const response = await fetch('https://api.example.com/user');

    // Parsing response as JSON
    const data = await response.json();

    // Logging the data
    console.log(data);
  } catch (error) {
    console.error('Failed to fetch data:', error);
  }
}

// Function call
fetchUserData();

In the above example, async declares an asynchronous function, and await waits for and then returns the result of the Promise.

If there is an issue with the fetch call or data parsing, the catch block handles the error.


Characteristics​

  1. Asynchronous Function: Declaring a function with async ensures the function always returns a Promise.

  2. Error Handling: Errors can be handled conveniently using a try/catch block.


Food Order Example​

You can illustrate the async/await pattern using a food ordering scenario.

  • async represents the function that takes orders.

  • await waits for the food (Promise) to be prepared in async.

  • try signifies the scenario where the food is served and eaten.

  • catch denotes the scenario where the food isn't served.

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