Chapter 1 Understanding "use strict"

JavaScript introduces a valuable feature designed to encourage better discipline in coding practices known as "use strict."

This directive serves to enforce a stricter parsing and error handling of your JavaScript code, ensuring that you adhere to best practices.

The "use strict" command is not just a statement but a literal expression, and it should be explicitly activated at the start of your code. When implemented, it signals the JavaScript engine to interpret the code in a stricter manner.

Section 1.1 How to Implement "use strict"

To utilize "use strict," simply insert the directive at the beginning of your script. You can use either double or single quotes, like this: "use strict" or 'use strict'. Once placed at the top, the entire script will operate under this modern approach.

Section 1.2 The Importance of "use strict"

There are vital reasons to adopt "use strict" in your coding practices. For instance, it's easy to forget to declare variables using var, let, or const. If you inadvertently create a variable without one of these keywords, it becomes an undeclared variable.

For example:

In strict mode, attempting to do so will raise an error, helping you avoid unintended issues.

Chapter 2 Benefits of Using "use strict"

The advantages of applying "use strict" are numerous, including:

• Preventing the use of undeclared variables.
• Restricting the use of JavaScript keywords as variable names.
• Disallowing the deletion of variables, objects, or functions with the delete keyword.
• Guarding against object creation without declaration.
• Prohibiting the deletion of properties.
• Preventing the use of octal numbers.
• Forbidding the use of duplicate parameter names in functions.

By incorporating "use strict" into your code, you can enhance its quality and maintainability, leading to a more efficient coding experience.