The Modern JavaScript Bootcamp (2019) - Working in Strict Mode

The video tutorial explains JavaScript's strict mode, highlighting its benefits in writing cleaner, error-free code. It demonstrates how to enable strict mode, handle errors, and future-proof code by avoiding reserved keywords. The tutorial also covers integrating strict mode into JavaScript files, ensuring better code quality and preventing common pitfalls.

What is one of the main benefits of using strict mode in JavaScript?

• It automatically fixes syntax errors.

• It makes the code run faster.

• It allows the use of deprecated features.

• It helps in writing cleaner and less error-prone code.

In the example provided, what happens when strict mode is enabled and an undeclared variable is assigned a value?

• A syntax error is thrown.

• The browser ignores the error.

• The variable is automatically declared globally.

• The code runs without any issues.

What is a 'leaked global' in the context of JavaScript?

• A variable that is intentionally declared globally.

• A variable that is shared between different scripts.

• A variable that is accidentally created in the global scope due to a typo.

• A variable that is declared but never used.

How does strict mode help in future-proofing JavaScript code?

• By automatically updating deprecated features.

• By preventing the use of future reserved keywords.

• By allowing the use of future reserved keywords.

• By making the code run on older browsers.

What happens to deprecated features when strict mode is enabled?

• They are automatically updated to newer versions.

• They are highlighted in the console.

• They are removed from the language.

• They are disabled, but not removed.

What is a recommended practice when integrating strict mode into JavaScript files?

• Use it only in new projects.

• Enable it only for global variables.

• Use it only for debugging purposes.

• Integrate it into all JavaScript files consistently.

Why is it beneficial to use strict mode consistently across all JavaScript files in an application?

• It allows for more flexible coding practices.

• It ensures all files run faster.

• It prevents any file from using deprecated features.

• It makes the code easier to read.