Is" use strict " still useful with the new features brought in EcmaScript 6?

Question

Is" use strict " still useful with the new features brought in EcmaScript 6?

EcmaScript 6 features let and const, which prevent variables from being unintentionally redeclared and overwritten, as well as limiting the scope of created variables.

The question is: with these changes in this new version is it still useful to use the use strict directive at the beginning of scripts?

1

javascript ecmascript-6

Author: raphael, 2019-05-12

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1 answers

score 4 · Accepted Answer

Is still useful because strict mode is not only related to variable declaration, such as let and const, but also to other situations where JavaScript without strict mode no exception is fired, although there is failure or it can be a typo, such as duplicating parameters of a function:

function f(a,b,a){}
// Uncaught SyntaxError: Duplicate parameter name not allowed in this context

Other stric mode utilities you can check out in this MDN documentation.