How to Correctly Structure Try...Catch Blocks with Async/Await in JavaScript?

Correct Syntax for Try...Catch Blocks with Async/Await

Asynchronous programming in JavaScript, facilitated by Async/Await, offers a convenient way to handle asynchronous operations. However, the placement of variables declared in try...catch blocks raises questions regarding best practices.

In the provided example, the variable createdUser is declared outside the try...catch block to allow its use after the await expression. However, the practice of incorporating multiple lines of business logic within the try body is generally discouraged.

Best Practice

The preferred approach is to encapsulate all asynchronous operations within the try block, ensuring that any exceptions are intercepted. This allows for comprehensive error handling and prevents logic placement outside the try block.

try {
  const createdUser = await this.User.create(userInfo);

  // Business logic can be placed here as exceptions will be caught.
  console.log(createdUser);
  // ... additional business logic ...
} catch (error) {
  console.error(error); // Handle error from creation or business logic.
}

Alternative Options

If it's essential to separate error handling from business logic, consider these alternatives:

• Declare the variable outside the block and assign it within the block.
• Test the caught exception type for specific handling or rethrowing.
• Utilize the .then() method with separate callbacks for fulfilled and rejected promises, providing a convenient and straightforward solution.

While a conditional exception syntax is not natively supported in JavaScript, custom error handling can be implemented by re-throwing exceptions within .catch() handlers if necessary.

The above is the detailed content of How to Correctly Structure Try...Catch Blocks with Async/Await in JavaScript?. For more information, please follow other related articles on the PHP Chinese website!