Question 23

Question

Can you explain the difference between async/await and traditional callbacks for handling asynchronous operations?

Answer

Both async/await and traditional callbacks achieve the goal, but they differ significantly in their syntax and how they feel to work with:

1. Traditional Callbacks:

• Syntax: A function is passed as an argument to an asynchronous operation, which is then executed when the operation completes (either successfully or with an error). This can lead to "callback hell" if you have nested operations.

• Example:

  function fetchData(url, callback) {
    setTimeout(() => {
      if (Math.random() < 0.8) { // Simulate success
        callback(null, "Data fetched!"); 
      } else {
        callback("Network error"); 
      }
    }, 1000);
  }
  
  fetchData('https://example.com/api', (error, data) => {
    if (error) {
      console.error(error);
    } else {
      console.log(data); 
    }
  });

• Pros: Simple for basic operations.

• Cons: Can become very difficult to read and manage as the number of asynchronous tasks increases (callback nesting). Error handling can be spread out and less clear.

2. async/await:

• Syntax: Uses async keyword before a function declaration to mark it as asynchronous. Inside, use await before an awaitable object (like a Promise) to pause execution until the result is available.

• Example:

  async function fetchData(url) {
    try {
      const response = await fetch(url); // Pause here until fetch completes
      const data = await response.json(); 
      return data;
    } catch (error) {
      console.error("Error fetching data:", error);
      throw error; // Re-throw the error to be handled elsewhere
    }
  }
  
  fetchData('https://example.com/api')
    .then(data => console.log(data))
    .catch(error => console.error("An error occurred:", error)); 

• Pros: Reads more like synchronous code, easier to understand and debug. Built-in error handling (try...catch). More organized and maintainable for complex asynchronous tasks.

• Cons: Requires a bit more setup (using async/await) compared to callbacks.

In Essence:

• Callbacks are older, less readable, prone to "callback hell."

• async/await is a more modern approach, providing cleaner syntax and better error handling for complex asynchronous scenarios.