Understanding the Difference between return and throw
When it comes to handling errors in functions, developers often wonder what's the difference between returning an error and throwing an error. Let's dive into the details.
Returning an Error
When you use return to return an error, it simply exits the function and returns the error value to the caller. The function execution is terminated, and the program flow is interrupted.
Example:
In this case, if sth is falsy, the function will return an error with the message "Error". The function execution will stop, and the error will be propagated up the call stack.
Throwing an Error
When you use throw to throw an error, it also interrupts the function execution, but it does so in a more drastic way. The error is propagated up the call stack, and the program will terminate immediately, unless caught by a try-catch block.
Example:
In this case, if sth is falsy, the function will throw an error with the message "Error". The error will be propagated up the call stack, and if not caught, the program will terminate.
Key Differences
Here are the key differences between returning an error and throwing an error:
- Function execution: Returning an error exits the function, while throwing an error interrupts the function execution and propagates the error up the call stack.
- Error propagation: Returning an error returns the error value to the caller, while throwing an error propagates the error up the call stack.
- Program flow: Returning an error terminates the function execution, while throwing an error can be caught by a
try-catchblock, allowing the program to continue execution.
In summary, returning an error is a more controlled way to handle errors, while throwing an error is a more drastic way to handle errors. Choose the approach that best fits your use case.
