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  • Edward Yasi thinks this is interesting:

 const​ book = {​  title: ​'Reasons and Persons'​,​  author: ​'Derek Parfit'​,​ };​ 

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Cover of Simplifying JavaScript

Note

Example of using spread operator to assign default values to an object, although default value of 1984 should come BEFORE ...book so if the book has a year it will be preserved.

See following highlight for final version that should actually be used.