How to Use `window` to Access JavaScript Libraries in the Console| Sabbirz

As JavaScript developers, we often rely on powerful libraries to enhance our applications. But sometimes, we need to inspect or interact with a library directly from the browser’s console. This is where the technique of exposing libraries to the window object becomes useful.

While it's a handy debugging method, it's essential to understand when (and when not) to use it.

What Does "Exposing to the Window Object" Mean?

Suppose you're using dayjs, a lightweight and popular date/time manipulation library. Here's how you'd expose it to the browser’s global scope:

import dayjs from 'dayjs';
window.dayjs = dayjs;

This code assigns the imported dayjs library to the window object, making it globally accessible as window.dayjs—or simply dayjs—from your browser console.

Try It Out in Your Console

Once you've exposed dayjs, open your browser’s console and experiment with the following:

Get the current date and time:
```
dayjs()
```
Format the date:
```
dayjs().format('YYYY-MM-DD')
```

Parse and format a specific date:

dayjs('2023-11-05').format('dddd, MMMM D, YYYY')

Play with other dayjs methods:

dayjs().add(7, 'day').format('YYYY-MM-DD')
dayjs().subtract(1, 'month').format('MMMM YYYY')
dayjs().diff(dayjs('2024-01-01'), 'days')

When to Use This Technique

✅ Use it for:

Debugging libraries or objects quickly in the browser
Prototyping or testing behavior without modifying core code
Teaching or demos where fast access improves learning

❌ Avoid in:

Production environments, as it can expose internals unnecessarily
Security-sensitive applications where global access should be limited

Final Thoughts

Exposing libraries to the window object is a simple, effective technique for development and debugging. Just remember to use it wisely and remove any global exposures before shipping your code to production.

Exposing JavaScript Libraries to Global Scope: Best Practices