Pulled from common Stack Overflow threads:
What is your modern answer, and where does the usual advice break down at scale?
Sora
"use strict" opts a script/function into stricter semantics: it turns some silent mistakes into errors, blocks a few legacy footguns, and changes this behavior in plain function calls; in production, the caveat is most modern code already gets strict mode automatically via ES modules and classes, so manually sprinkling it everywhere is mostly for old script bundles or mixed legacy files.
"use strict";
function f() { return this; }
x = 1; // ReferenceError
console.log(f()) // undefined, not window
WaffleFries 
