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Ray
Ray

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React learning note: Logical Operators

Hello, everyone! Sorry for stopping updating for a couple of weeks while I was busy with finals a while back, I'll try to get back to a weekly update as often as I can later on. In the meantime, I've been offered a summer internship at BOPRC, so if I gain any new understandings during the internship, I'll be blogging about them as well~!

Back to our React study notes. Logical Operators are used quite frequently in React programming.
The 'end Operator' and 'or Operator' have a feature called: short-circuiting, short-circuiting In logical Operators, in certain conditions the operator will return the first value.

'end Operator'

console.log(false && "hello");
console.log(true && "hello");
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'hasMovieAdaptation' is the variable we defined earlier, and we can also use it as an end operator, more like 'if'.
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This syntax also applies to truthy and falsy Values, eg:
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'or Operator'
The 'or operator' is the inverse case and returns the first upper end as long as it is true

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We can use this feature to define default values for specific data. For example:
A book with an ID of 2 has no Spanish translation
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Also works for undefined values
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There is also a notation: nullish coalescing operator, which works much like 'or operator', but it does also short circuit or falsy value

const count = book.reviews.librarything.rating.reviewsCount ?? "No data here";
count;
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