Know Your Enemy

When an error occurs, JavaScript creates an error object and passes it to the catch block. This object contains detailed information about what went wrong.

Key Properties

Property	Description
name	The error type (e.g., ReferenceError, SyntaxError, TypeError)
message	A human-readable description of the error
stack	The full call stack trace — which function called which

try {
  const data = JSON.parse('{ invalid json }');
} catch (err) {
  console.log(err.name);    // SyntaxError
  console.log(err.message); // Unexpected token i in JSON...
  console.log(err.stack);   // Full stack trace
}

Throwing Your Own Errors

function divide(a, b) {
  if (b === 0) {
    throw new Error('Division by zero is not allowed!');
  }
  return a / b;
}

try {
  console.log(divide(10, 0));
} catch (err) {
  console.log('Caught: ' + err.message);
}