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Do we have to write use strict in all of the functions we have in our JS files or would writing it at the top of the code be enough to validate everything?

Soheila Tarighi
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Leilena Tekle
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    Does this answer your question? [What does "use strict" do in JavaScript, and what is the reasoning behind it?](https://stackoverflow.com/questions/1335851/what-does-use-strict-do-in-javascript-and-what-is-the-reasoning-behind-it) – Triby Mar 30 '20 at 23:36

3 Answers3

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You only need to add it once at the top of the file.

See this link: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Strict_mode

Strict mode applies to entire scripts or to individual functions.

To invoke strict mode for an entire script, put the exact statement "use strict"; (or 'use strict';) before any other statements.

// Whole-script strict mode syntax
'use strict';
var v = "Hi! I'm a strict mode script!";
Community
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sunknudsen
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0

'use strict' is lexically inherited, just like variable scope. A function will run in strict mode if it contains use strict or if an ancestor block has use strict. You only need to write it once.

(() => {
  'use strict';
  // put all your code here
})();

For front-end, if you have lots of code for which putting it all in a single file would seem too unwieldy, consider using a bundler like Webpack, which can let you write scripts in separate files and then combines them into a single strict bundle.

For Node, you do have to write 'use strict' at the top of every file, unfortunately.

CertainPerformance
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0

For Node.js you will have to wirte use strict; at top of every file

for more reference https://stackoverflow.com/a/30634600/12904989

Hardik Shah
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mad max
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