Error Handling (try, catch, and finally, throw)
Expert-Level Explanation
Error handling in JavaScript is done using try
, catch
, finally
, and throw
. try
wraps code that may throw an error. catch
is used to handle any errors that occur. finally
contains code that runs regardless of the result. throw
is used to generate custom errors.
Creative Explanation
Think of error handling as a safety net in a circus. The acrobat (code) performs a routine (tries something). If they slip (an error occurs), the safety net (catch
) catches them. The show goes on (finally
), regardless of whether the acrobat falls or not. Sometimes, the acrobat might deliberately jump into the net (throw
) to show a planned trick.
Practical Explanation with Code
try {
// Code that may throw an error
let result = someFunction();
} catch (error) {
// Code to handle the error
console.log('An error occurred:', error.message);
} finally {
// Code that runs regardless of the result
console.log('This always runs');
}
// Throwing a custom error
if (someCondition) {
throw new Error('Custom error message');
}
Real-world Example
Imagine error handling like a GPS navigation system. If it encounters a roadblock (error), it recalculates the route (catch
). Regardless of the route, you reach your destination or a dead-end (finally
). Sometimes, you might choose to take a detour (throw
) if you know the road is bad.