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Discussion on: What is {x:1} and why does it return 1 🤷‍♂️

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jcubic profile image
Jakub T. Jankiewicz • • Edited

You may think that this actually doesn't matter much, because it never happen in real code, but this is really important for arrow functions:

const fn = () => {x: 1};
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this is a function that return undefined not object, because it's block with label and no return.

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patarapolw profile image
Pacharapol Withayasakpunt •

Good linters will tell.

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Jakub T. Jankiewicz •

This is what ESLint will tell you, you got errors but you may have no clue what they mean:

  5922:39  error  'x:' is defined but never used                    no-unused-labels
  5922:39  error  This line has 2 statements. Maximum allowed is 1  max-statements-per-line
  5922:42  error  Missing semicolon                                 semi
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h43z profile image
h43z •

ohhh... good to know. Thank you!