What is the difference between throw new Error and throw someObject?

Direct comparison

Cross-browser consistency with Error objects

The moment you throw new Error, JavaScript promptly creates an Error object bristling with a stack trace, all neatly bundled in a format consistent across all browsers. Imagine this consistency like drinking a finely-made espresso shot providing that much-needed debugging caffeine boost.

Flexibility with objects

Throwing someObject opens up a world of possibilities where you can include custom properties specific to your application context. However, this flexibility comes with a price - no stack trace, transforming debugging from a methodical investigation into a treacherous maze.

Serialize and shine

If your error gets logged at a central location (like log aggregators and debuggers), their serialization becomes crucial. Throwing standard new Error ensures your error enhances its modeling career by posing predictably for serializations. Without throwing plain objects or strings, the modeling career of your error could start mimicking unpredictable weather patterns.

Decoding error objects' names

An Error object name property could reveal one of six names: EvalError, RangeError, ReferenceError, SyntaxError, TypeError, URIError. Each name hints at a specific type of error in JavaScript, helping you navigate the debugging journey better and faster, akin to those helpful directions from your sat nav.

Craft custom exceptions with catch blocks

Thanks to JavaScript, throwing your exceptional exceptions allows you to control with precision your program's control flow to catch blocks. You can now handle not just built-in error types but also set the custom logic to handle something like an “oops, our coffee machine is out of coffee beans” situation.

Error objects for all seasons?

Whether you're pushing your code to the next JavaScript framework or preparing it for a late-night coding session, using Error objects is your best bet for throwing errors. Not only they explain the intent and context of the error but also gel smoothly with error handling mechanisms like try/catch and Promises.

Remember, options always exist. Some developers prefer the serene path of returning error objects or marching with callback functions for passing errors.

Delving into advanced error handling strategies

Creating custom error classes

Beyond the realm of basic Error objects, welcome custom error classes. Adding additional context or behaviors to your errors makes debugging a less gloomy affair and more like an informative treasure chest.

For example, you can define a CustomError class:

class CustomError extends Error {
  constructor(message, code) {
    super(message);
    this.code = code;
  }
}

try {
  // Here's where we start throwing toys out of the pram!
  throw new CustomError('Code RED! 🚨', 500);
} catch (e) {
  // Handle the custom error as if it was an octopus 🐙 on your face
}


With custom errors, you adhere to the single-responsibility principle, separating tantrum-throwing errors from the rest of your slightly more mature code.

Handling errors in promises

When diving into the asynchronous waters of JavaScript Promises, make friends with Promise rejections and handle them with .catch() or with a life jacket of async/await and try/catch.

myAsyncFunction()
  .then(result => {
    // Process result, party time 🎉
  })
  .catch(error => {
    // Handle error, back to the grind 😔
  });


Handle errors in Promises like they are ticking time bombs, ensuring they are defused carefully and conscientiously.

A unified approach to error handling

If your error potential is as diverse as the species in the Amazon, consider a centralized error handling mechanism that works like an efficient forest ranger. It could either be a global error handler or error processing middleware if you're rolling with the Express.js gang.

This helps ensure that all errors are rounded up, tagged, and identified consistently, paving the way for smoother logging, auditing, or user feedback.