Salesforce JavaScript Developer Practice Exam

Where can you use the await keyword and what does it do?

1. Inside synchronous functions to pause execution

2. Inside async functions to wait for a promise to resolve

3. At the top level of a script to start an async process

4. In any function to handle errors

The correct answer is: Inside async functions to wait for a promise to resolve

The await keyword is specifically designed to be used within async functions. When you incorporate await before a promise, it pauses the execution of the async function until that promise is resolved. This allows for cleaner and more readable asynchronous code since it avoids the need for chaining .then() calls and makes it look more synchronous. Using await in an async function effectively turns the asynchronous operation into a behavior that feels synchronous—meaning that the function halts its execution at the await statement until the awaited promise resolves, at which point execution resumes. This is particularly valuable when you need the result of the asynchronous operation immediately following the await statement to proceed with your code logic, allowing you to write more straightforward and manageable code. In contrast to the other choices, the await keyword cannot operate outside of async functions, making that choice inaccurate. Also, while you can start async processes at the top level in some environments (such as ES modules in modern JavaScript), it's not the typical or recommended use of await. Furthermore, await is not designed to handle errors; error handling in JavaScript async functions is normally done using try/catch blocks surrounding the await call. By understanding these distinctions, the use of the await keyword becomes a more powerful tool for managing asynchronous JavaScript operations effectively.