Problem Statement
What is strict mode "use strict" and what does it change?
Explanation
Strict mode, enabled by the directive "use strict";, is a feature in JavaScript introduced in ECMAScript 5 that enforces stricter parsing and error handling on code at runtime. It helps developers write cleaner, safer, and more secure code by catching common mistakes and enforcing a more robust set of rules.
trict mode makes several changes to normal JavaScript semantics:
Eliminates some JavaScript silent errors by changing them to throw errors.
Fixes mistakes that make it difficult for JavaScript engines to perform optimizations: strict mode code can sometimes be made to run faster than identical code that's not strict mode.
Prohibits some syntax likely to be defined in future versions of ECMAScript.
Practice Sets
This question appears in the following practice sets: