Understanding this in JavaScript — Made Simple with Real Examples! Most Asked Interview Questions

Try to guess the answers to the following most commonly asked questions in interviews.

📌 1. Strict Mode + Regular Function

📌 2. Object Method vs Arrow Function

📌 3. Arrow Function Inside Method

📌 4. setTimeout + Regular Function

📌 5. Destructured Method Loses Context

📌 6. Class + setTimeout

📌 7. Fixing this inside nested functions

✅ Fix using arrow or bind:

📌 8. Arrow functions do NOT bind this

📌 9. map + this context

✅ Fix with arrow:

📌 10. Arrow Function from Class Method

Conclusion:

Key Observations from Code Examples

• Arrow functions do not bind their own this. They inherit from the lexical (outer) scope.

• Regular functions inside setTimeout, map, or nested scopes lose this unless bound explicitly.

• Destructuring methods from objects can detach them from their original context → leading to undefined this.

• Use .bind(), call(), or arrow functions to retain proper context in callbacks or asynchronous functions.