Error Handling – try/catch, Custom Errors & Debugging

Synchronous errors are caught with try…catch.

try { JSON.parse(badJSON); }
catch(e){ console.error('Invalid JSON', e); }

Asynchronous errors (Promises) use .catch() or try…catch inside async/await.

Custom Error classes:

class ValidationError extends Error {
  constructor(message){ super(message); this.name='ValidationError'; }
}
throw new ValidationError('Invalid input');

Debugging tools

• console.log, console.table, console.group.
• debugger; statement – pauses execution when DevTools are open.
• Chrome DevTools → Sources → Breakpoints.