5 ms·

To me personally, the use case for ?: is selecting a value for a const: const value = cond ? a : b; Using an if instead would mean you can't make it const

by 8372049 3y ago

To me personally, the use case for ?: is selecting a value for a const: const value = cond ? a : b; Using an if instead would mean you can't make it const, and is usually more convoluted to read. For pretty much all other use cases, I agree that ifs are better.

kevindamm 3y ago
In that case you can have the result of a function call be assigned to the const, and the function be the if/else for the value. With a well-named function it can even be more readable than the ternary.
- IlliOnato 3y ago
  Having to create a function where a simple expression would suffice is "typing in mittens" programming...
  - kevindamm 3y ago
    Fair enough.. I actually use ternary sometimes, especially in brief return statements, and especially when both results are simple values. I only really avoid it when the result expressions are multiline. I just felt like pointing out the obvious when I saw GP's comment.
zogrodea 3y ago
I was confused by your reply when I first read it (didn't quite understand it), but I think it comes from a miscommunication when I had intended if-expressions (if statements that return a value) while you had if-statements in mind. For example, the following F# code (you can run `dotnet fsi` in a terminal to try it out, if you have dotnet installed) is equivalent to a ternary expression: // the value of x is "is_not_lower" after evaluation (x is a constant/immutable value, just like a 'const' value in JS) let x = if 0 > 1 then "is_lower" else "is_not_lower" Which is equivalent to the following (in JS): const x = 0 > 1 ? "is_lower" : "is_not_lower" In F# (and also Kotlin which I linked before), you can have clean code with if-elif-else ladders while the equivalent (using nested ternaries) would be hard to read. For example: // the constant/immutable variable "comparison" is either "HIGHER", "LOWER" or "EQUAL" depending on the branch taken let comparison = if a > b then "HIGHER" elif a < b then "LOWER" else "EQUAL" In JS land (and also most common programming languages which have plain if-statements), I agree a ternary would often be preferrable as long as it's not nested.
- IlliOnato 3y ago
  I would say that languages where "if" can be used as expression provide a different (perhaps better) syntax for the same ternary operator. a = if x then y else z is just a more verbose version of a = x ? y : z; Raku uses yet another form of the same operator: a = x ?? y :: z; Syntactic sugar :-)
  - lizmat 3y ago
    It's actually a = x ?? y !! z And that's because a single : is used for many other semantics in the Raku Programming Language. And ?? and !! standout better in code. https://docs.raku.org/language/operators#infix_??_ https://docs.raku.org/language/operators#infix_??_!!
    - IlliOnato 3y ago
      You are right, of course. Sorry! "Colon belongs to Larry" :-) I think I made this mistake because :: was used in one of the drafts for Perl 6, but the final specification uses !!
- 8372049 3y ago
  Sorry for the confusion, but you did indeed decipher my meaning (if-statements)! I agree that if-expressions are far more readable in languages that support them (Python and Haskell come to mind for me), even though they're arguably just syntactic sugar for the ternary operator.

kevindamm 3y ago

In that case you can have the result of a function call be assigned to the const, and the function be the if/else for the value. With a well-named function it can even be more readable than the ternary.

IlliOnato 3y ago
Having to create a function where a simple expression would suffice is "typing in mittens" programming...
- kevindamm 3y ago
  Fair enough.. I actually use ternary sometimes, especially in brief return statements, and especially when both results are simple values. I only really avoid it when the result expressions are multiline. I just felt like pointing out the obvious when I saw GP's comment.

zogrodea 3y ago

I was confused by your reply when I first read it (didn't quite understand it), but I think it comes from a miscommunication when I had intended if-expressions (if statements that return a value) while you had if-statements in mind. For example, the following F# code (you can run `dotnet fsi` in a terminal to try it out, if you have dotnet installed) is equivalent to a ternary expression: // the value of x is "is_not_lower" after evaluation (x is a constant/immutable value, just like a 'const' value in JS) let x = if 0 > 1 then "is_lower" else "is_not_lower" Which is equivalent to the following (in JS): const x = 0 > 1 ? "is_lower" : "is_not_lower" In F# (and also Kotlin which I linked before), you can have clean code with if-elif-else ladders while the equivalent (using nested ternaries) would be hard to read. For example: // the constant/immutable variable "comparison" is either "HIGHER", "LOWER" or "EQUAL" depending on the branch taken let comparison = if a > b then "HIGHER" elif a < b then "LOWER" else "EQUAL" In JS land (and also most common programming languages which have plain if-statements), I agree a ternary would often be preferrable as long as it's not nested.

IlliOnato 3y ago
I would say that languages where "if" can be used as expression provide a different (perhaps better) syntax for the same ternary operator. a = if x then y else z is just a more verbose version of a = x ? y : z; Raku uses yet another form of the same operator: a = x ?? y :: z; Syntactic sugar :-)
- lizmat 3y ago
  It's actually a = x ?? y !! z And that's because a single : is used for many other semantics in the Raku Programming Language. And ?? and !! standout better in code. https://docs.raku.org/language/operators#infix_??_ https://docs.raku.org/language/operators#infix_??_!!
  - IlliOnato 3y ago
    You are right, of course. Sorry! "Colon belongs to Larry" :-) I think I made this mistake because :: was used in one of the drafts for Perl 6, but the final specification uses !!
8372049 3y ago
Sorry for the confusion, but you did indeed decipher my meaning (if-statements)! I agree that if-expressions are far more readable in languages that support them (Python and Haskell come to mind for me), even though they're arguably just syntactic sugar for the ternary operator.