try...catch
The try block contains code that might throw. If an error occurs, execution jumps to the catch block.
try {
let result = 10 / 0;
console.log(result);
throw new Error("Manual error");
} catch (error) {
console.log("Caught:", error.message);
}finally
The finally block runs regardless of whether an error was thrown or caught. It's perfect for cleanup.
function divide(a, b) {
try {
if (b === 0) throw new Error("Division by zero");
return a / b;
} catch (err) {
console.log(err.message);
return null;
} finally {
console.log("Cleanup complete");
}
}
console.log(divide(10, 2));
console.log(divide(10, 0));throw
You can throw anything: strings, numbers, booleans, or Error objects. Throwing an Error object is best practice.
function validateAge(age) {
if (age < 0) throw new Error("Age cannot be negative");
if (age < 18) throw new Error("Must be 18 or older");
return "Valid age";
}
try {
console.log(validateAge(15));
} catch (err) {
console.log("Validation error:", err.message);
}