JavaScript Error Handling Best Practices
Learn how to properly handle errors in JavaScript applications.
Try/Catch Basics
try {
// Code that might throw
riskyOperation();
} catch (error) {
console.error('Error:', error.message);
} finally {
// Always runs
cleanup();
}
Custom Errors
class ValidationError extends Error {
constructor(message) {
super(message);
this.name = 'ValidationError';
}
}
Async Error Handling
async function fetchData() {
try {
const response = await fetch(url);
if (!response.ok) {
throw new Error('Network error');
}
return await response.json();
} catch (error) {
handleError(error);
}
}
Error Types
- SyntaxError: Invalid code syntax - ReferenceError: Undefined variable - TypeError: Wrong type operation - RangeError: Number out of range
Best Practices
- Be specific with error messages - Log errors for debugging - Fail gracefully with user feedback - Never swallow errors silently