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Gah.. I hate the ternary operator. Not that it's necessarily a bad thing in and of itself, but every time I've come across it in code, I've ultimately had to y

Gah.. I hate the ternary operator. Not that it's necessarily a bad thing in and of itself, but every time I've come across it in code, I've ultimately had to yank it out because I've needed to support an additional possibility. I don't get what value it really supplies, and it seems like people are really fond of using it in the wrong places.

userbinator 9y ago
I don't get what value it really supplies, and it seems like people are really fond of using it in the wrong places. It's a conditional expression , not a statement, and particularly helps simplify things like if(foo) someVeryVeryLongExpressionEvaluatingToAnLvalue = someShortRvalue; else someVeryVeryLongExpressionEvaluatingToAnLvalue = otherShortRvalue into someVeryVeryLongExpressionEvaluatingToAnLvalue = foo ? someShortRvalue : otherShortRvalue; I suppose to really "get" what the ternary is useful for, you have to have some experience with a more functional programming language, focusing on the flow of the data itself. There, multiply-nested ternaries are really the norm for what you'd otherwise call "control flow" in non-functional languages, and structures like this are common: value = isAtrue ? A_value : isBtrue ? B_value : isCtrue ? C_value : D_value ; (Does not work in PHP, but every other language with a ternary will interpret that as a compact alternative to the far more cumbersome if/else --- especially if coding standards dictate braces on their own line.)
- skocznymroczny 9y ago
  I don't like the ternary operator ?, because it's not obvious: xyz = foo ? bar : baz; What does it mean? Which is the condition? which is the true, which is the false value? It's not obvious. In Python it is much more clearer: xyz = bar if foo else baz
  - bshimmin 9y ago
    I honestly struggle to understand how a traditional ternary like this isn't obvious. The bit before the question mark is the condition (er, like a question, which ends with a question mark), then the other two bits are for true and false in the order you would expect. I will freely admit I try and avoid nested ternaries, which I personally find hard to read.
  - evincarofautumn 9y ago
    I never really understood the distaste for it, or how it’s non-obvious. It seems like the people I’ve talked to object to the punctuation-based syntax more than the semantics, because it exactly mirrors conditional statements, even when nested. (Well, except in PHP, but that’s a bug in the grammar.) if (a) { b } else if (c) { d } else { e } a ? b : c ? d : e if (a) { b } else { if (c) { d } else { e } } a ? b : ( c ? d : e ) The question mark goes after the thing you’re asking about, like in English. The colon to separate the true and false branches is totally arbitrary, I grant you. I’d prefer to have the if…else notation available as an expression, but the statement-expression distinction hasn’t quite died yet. Personally, I don’t care for Python’s version with the condition and true branch swapped, because I read it like invalid Forth, expecting “condition IF true-branch ELSE false-branch THEN”. :P
pveierland 9y ago
In C it's useful as it allows you to still const a variable when assigning a value conditionally. const int x = a ? 1 : 2;
seanwilson 9y ago
The ternary operator can be nice for conciseness and to ensure a variable has been assigned to when the language doesn't check that for you e.g. var x = condition ? 1 : 2; vs var x; if (condition) x = 1 else x = 2 I miss being able to write code like this in languages like OCaml: let x = if (condition) then // more lines of code 1 else 2
- girvo 9y ago
  Heh your OCaml example is why I adore Nim, and any other languages that "expression all the things!" -- even modern JavaScript is decent on this front with 'ramda' and my favourite helper library @unction: https://github.com/krainboltgreene/unction.js/blob/core/README.md https://github.com/krainboltgreene/unction.js/blob/core/READ... Between those two, consise readable functional JS code based entirely around expressions is simple to achieve. It's genuinely made me happy to be back in JS land
hinkley 9y ago
I managed to go about 15 years without using the ternary operator. Pretty much the only time it's really good at what it does is for assignments, and I've started using it a bit myself. However, the old discomforts come up pretty frequently. I find people slipping functions into both the right hand and left hand side. And once you do that, you really should push it into a new function. Especially if you have any plans for testing. Most compilers are pretty good at inlining things like that, and at any rate there are almost always bigger performance problems than function call overhead. In fact, one of my big tricks is that a function that consists of a weird but fast algorithm is generally tolerated by your coworkers better than just dropping it into the middle of a block of code. And knowing they could easily revert the change (because it's only one commit and one function body!) if it starts to annoy them also helps. tl;dr: Just like comments in the middle of a function reveal a missing function, a ternary operator probably means the same.

userbinator 9y ago

I don't get what value it really supplies, and it seems like people are really fond of using it in the wrong places. It's a conditional expression , not a statement, and particularly helps simplify things like if(foo) someVeryVeryLongExpressionEvaluatingToAnLvalue = someShortRvalue; else someVeryVeryLongExpressionEvaluatingToAnLvalue = otherShortRvalue into someVeryVeryLongExpressionEvaluatingToAnLvalue = foo ? someShortRvalue : otherShortRvalue; I suppose to really "get" what the ternary is useful for, you have to have some experience with a more functional programming language, focusing on the flow of the data itself. There, multiply-nested ternaries are really the norm for what you'd otherwise call "control flow" in non-functional languages, and structures like this are common: value = isAtrue ? A_value : isBtrue ? B_value : isCtrue ? C_value : D_value ; (Does not work in PHP, but every other language with a ternary will interpret that as a compact alternative to the far more cumbersome if/else --- especially if coding standards dictate braces on their own line.)

skocznymroczny 9y ago
I don't like the ternary operator ?, because it's not obvious: xyz = foo ? bar : baz; What does it mean? Which is the condition? which is the true, which is the false value? It's not obvious. In Python it is much more clearer: xyz = bar if foo else baz
- bshimmin 9y ago
  I honestly struggle to understand how a traditional ternary like this isn't obvious. The bit before the question mark is the condition (er, like a question, which ends with a question mark), then the other two bits are for true and false in the order you would expect. I will freely admit I try and avoid nested ternaries, which I personally find hard to read.
- evincarofautumn 9y ago
  I never really understood the distaste for it, or how it’s non-obvious. It seems like the people I’ve talked to object to the punctuation-based syntax more than the semantics, because it exactly mirrors conditional statements, even when nested. (Well, except in PHP, but that’s a bug in the grammar.) if (a) { b } else if (c) { d } else { e } a ? b : c ? d : e if (a) { b } else { if (c) { d } else { e } } a ? b : ( c ? d : e ) The question mark goes after the thing you’re asking about, like in English. The colon to separate the true and false branches is totally arbitrary, I grant you. I’d prefer to have the if…else notation available as an expression, but the statement-expression distinction hasn’t quite died yet. Personally, I don’t care for Python’s version with the condition and true branch swapped, because I read it like invalid Forth, expecting “condition IF true-branch ELSE false-branch THEN”. :P

pveierland 9y ago

In C it's useful as it allows you to still const a variable when assigning a value conditionally. const int x = a ? 1 : 2;

seanwilson 9y ago

The ternary operator can be nice for conciseness and to ensure a variable has been assigned to when the language doesn't check that for you e.g. var x = condition ? 1 : 2; vs var x; if (condition) x = 1 else x = 2 I miss being able to write code like this in languages like OCaml: let x = if (condition) then // more lines of code 1 else 2

girvo 9y ago
Heh your OCaml example is why I adore Nim, and any other languages that "expression all the things!" -- even modern JavaScript is decent on this front with 'ramda' and my favourite helper library @unction: https://github.com/krainboltgreene/unction.js/blob/core/README.md https://github.com/krainboltgreene/unction.js/blob/core/READ... Between those two, consise readable functional JS code based entirely around expressions is simple to achieve. It's genuinely made me happy to be back in JS land

hinkley 9y ago

I managed to go about 15 years without using the ternary operator. Pretty much the only time it's really good at what it does is for assignments, and I've started using it a bit myself. However, the old discomforts come up pretty frequently. I find people slipping functions into both the right hand and left hand side. And once you do that, you really should push it into a new function. Especially if you have any plans for testing. Most compilers are pretty good at inlining things like that, and at any rate there are almost always bigger performance problems than function call overhead. In fact, one of my big tricks is that a function that consists of a weird but fast algorithm is generally tolerated by your coworkers better than just dropping it into the middle of a block of code. And knowing they could easily revert the change (because it's only one commit and one function body!) if it starts to annoy them also helps. tl;dr: Just like comments in the middle of a function reveal a missing function, a ternary operator probably means the same.