What does 'use strict' do?
- A Enables faster execution mode
- B Enforces stricter parsing and error handling, such as preventing undeclared variables
- C Disables all warnings
- D Enables TypeScript features
Answer
Enforces stricter parsing and error handling, such as preventing undeclared variables
Strict mode turns silent errors into throws, forbids undeclared variables, and makes this undefined in plain function calls. ES modules are strict by default.





