What is Use Strict Mode in JavaScript | JavaScript Tutorials in Hindi | Interview Question #17

In JavaScript, “use strict” is a directive that enables strict mode, a stricter and safer version of the language. When you use the “use strict” directive at the beginning of your script or function, you are telling the JavaScript engine to enforce a stricter set of rules for parsing and executing your code. This helps to prevent common mistakes and encourages you to write more secure and reliable code.

Strict mode introduces several changes to the way JavaScript works, including:

Variables must be declared before they are used.
Deleting a variable or function is not allowed.
Assigning a value to an undeclared variable is not allowed.

In general, using strict mode is a good practice that can help you catch errors earlier and write more maintainable code. However, it’s important to note that not all browsers support strict mode, so you may need to test your code carefully to ensure that it works correctly across different environments.