Benefits of using the conditional ternary operator

Question

What are the benefits and drawbacks of the    operator as opposed to the standard if-else statement  The obvious ones being   Conditional    Operator   Shorter and more concise when dealing with direct value comparisons and assignments Doesn t seem to be as flexible as the if else construct   Standard If Else   Can be applied to more situations  such as function calls   Often are unnecessarily long   Readability seems to vary for each depending on the statement  For a little while after first being exposed to the    operator  it took me some time to digest exactly how it worked  Would you recommend using it wherever possible  or sticking to if else given that I work with many non-programmers

User · Answer

The scenario I most find myself using it is for defaulting values and especially in returns

return someIndex < maxIndex ? someIndex : maxIndex;

Those are really the only places I find it nice, but for them I do.

Though if you're looking for a boolean this might sometimes look like an appropriate thing to do:

bool hey = whatever < whatever_else ? true : false;

Because it's so easy to read and understand, but that idea should always be tossed for the more obvious:

bool hey = (whatever < whatever_else);

User · Answer

The ternary operator can be included within an rvalue  whereas an if-then-else cannot  on the other hand  an if-then-else can execute loops and other statements  whereas the ternary operator can only execute  possibly void  rvalues   On a related note  the  amp  amp  and    operators allow some execution patterns which are harder to implement with if-then-else   For example  if one has several functions to call and wishes to execute a piece of code if any of them fail  it can be done nicely using the  amp  amp  operator   Doing it without that operator will either require redundant code  a goto  or an extra flag variable

User · Answer

I would basically recommend using it only when the resulting statement is extremely short and represents a significant increase in conciseness over the if else equivalent without sacrificing readability   Good example   int result   Check     1   0    Bad example   int result   FirstCheck     1   SecondCheck     1   ThirdCheck     1   0

User · Answer

There is some performance benefit of using the the   operator in eg  MS Visual C    but this is a really a compiler specific thing  The compiler can actually optimize out the conditional branch in some cases

User · Answer

Sometimes it can make the assignment of a bool value easier to read at first glance      With button IsEnabled   someControl HasError   false   true      Without button IsEnabled    someControl HasError

User · Answer

This is pretty much covered by the other answers  but  it s an expression  doesn t really explain why that is so useful     In languages like C   and C   you can define local readonly fields  within a method body  using them  This is not possible with a conventional if then statement because the value of a readonly field has to be assigned within that single statement   readonly int speed    shiftKeyDown    10   1    is not the same as   readonly int speed    if  shifKeyDown        speed   10        error - can t assign to a readonly else       speed   1         error     In a similar way you can embed a tertiary expression in other code  As well as making the source code more compact  and in some cases more readable as a result  it can also make the generated machine code more compact and efficient   MoveCar  shiftKeyDown    10   1        may generate less code than having to call the same method twice   if  shiftKeyDown      MoveCar 10   else     MoveCar 1     Of course  it s also a more convenient and concise form  less typing  less repetition  and can reduce the chance of errors if you have to duplicate chunks of code in an if else   In clean  common pattern  cases like this   object thing    reference    null    null   reference Thing        it is simply faster to read parse understand  once you re used to it  than the long-winded if else equivalent  so it can help you to  grok  code faster   Of course  just because it is useful does not mean it is the best thing to use in every case  I d advise only using it for short bits of code where the meaning is clear  or made more clear  by using    - if you use it in more complex code  or nest ternary operators within each other it can make code horribly difficult to read

User · Answer

The advantage of the conditional operator is that it is an operator  In other words  it returns a value  Since if is a statement  it cannot return a value

User · Answer

A really cool usage is   x   foo   1       bar   2       baz   3             4

User · Answer

The conditional operator is great for short conditions  like this   varA   boolB   valC   valD    I use it occasionally because it takes less time to write something that way    unfortunately  this branching can sometimes be missed by another developer browsing over your code  Plus  code isn t usually that short  so I usually help readability by putting the   and   on separate lines  like this   doSomeStuffToSomething shouldSomethingBeDone         getTheThingThatNeedsStuffDone         getTheOtherThingThatNeedsStuffDone       However  the big advantage to using if else blocks  and why I prefer them  is that it s easier to come in later and add some additional logic to the branch   if  shouldSomethingBeDone          doSomeStuffToSomething getTheThingThatNeedsStuffDone         doSomeAdditionalStuff      else   doSomeStuffToSomething getTheOtherThingThatNeedsStuffDone         or add another condition   if  shouldSomethingBeDone          doSomeStuffToSomething getTheThingThatNeedsStuffDone         doSomeAdditionalStuff      else if  shouldThisOtherThingBeDone         doSomeStuffToSomething getTheOtherThingThatNeedsStuffDone         So  in the end  it s about convenience for you now  shorter to use     vs  convenience for you  and others  later  It s a judgment call    but like all other code-formatting issues  the only real rule is to be consistent  and be visually courteous to those who have to maintain  or grade   your code    all code eye-compiled

User · Answer

If you need multiple branches on the same condition  use an if   if  A    6    f 1  2  3   else   f 4  5  6     If you need multiple branches with different conditions  then if statement count would snowball  you ll want to use the ternary   f   A    6   1  4   B    6   2  5   C    6   3  6      Also  you can use the ternary operator in initialization   const int i    A    6   1   4    Doing that with if is very messy   int i temp  if  A    6     i temp   1  else    i temp   4  const int i   i temp    You can t put the initialization inside the if else  because it changes the scope   But references and const variables can only be bound at initialization

User · Answer

I usually choose a ternary operator when I d have a lot of duplicate code otherwise   if  a  gt  0      answer   compute a  b  c  d  e   else     answer   compute -a  b  c  d  e     With a ternary operator  this could be accomplished with the following   answer   compute a  gt  0   a   -a  b  c  d  e

User · Answer

With C  7  you can use the new ref locals feature to simplify the conditional assignment of ref-compatible variables  So now  not only can you do   int i   0   T b   default T   c   default T       initialization of C 7  ref-local  variable using a conditional r-value      ref T a   ref  i    0   ref b   ref c        but also the extremely wonderful      assignment of l-value     conditioned by C 7  ref-locals    i    0   ref b   ref c    a    That line of code assigns the value of a to either b or c  depending on the value of i     Notes 1  r-value is the right-hand side of an assignment  the value that gets assigned  2  l-value is the left-hand side of an assignment  the variable that receives the assigned value

User · Answer

One thing to recognize when using the ternary operator that it is an expression not a statement    In functional languages like scheme the distinction doesn t exists    if    a b  a b   Conditional    Operator  Doesn t seem to be as flexible as the if else construct   In functional languages it is   When programming in imperative languages I apply the ternary operator in situations where I typically would use expressions  assignment  conditional statements  etc

User · Answer

I d recommend limiting the use of the ternary     operator to simple single line assignment if else logic   Something resembling this pattern   if  lt boolCondition gt          lt variable gt     lt value gt     else        lt variable gt     lt anotherValue gt       Could be easily converted to    lt variable gt     lt boolCondition gt     lt value gt     lt anotherValue gt     I would avoid using the ternary operator in situations that require if else if else  nested if else  or if else branch logic that results in the evaluation of multiple lines   Applying the ternary operator in these situations would likely result in unreadable  confusing  and unmanageable code   Hope this helps

User · Answer

If I m setting a value and I know it will always be one line of code to do so  I typically use the ternary  conditional  operator  If there s a chance my code and logic will change in the future  I use an if else as it s more clear to other programmers    Of further interest to you may be the    operator

User · Answer

I find it particularly helpful when doing web development if I want to set a variable to a value sent in the request if it is defined or to some default value if it is not

User · Answer

While the above answers are valid  and I agree with readability being important  there are 2 further points to consider    In C 6  you can have expression-bodied methods     This makes it particularly concise to use the ternary   string GetDrink DayOfWeek day        gt  day    DayOfWeek Friday          Beer     Tea      Behaviour differs when it comes to implicit type conversion    If you have types T1 and T2 that can both be implicitly converted to T  then the below does not work   T GetT     gt  true   new T1     new T2       because the compiler tries to determine the type of the ternary expression  and there is no conversion between T1 and T2    On the other hand  the if else version below does work   T GetT        if  true  return new T1       return new T2        because T1 is converted to T and so is T2

[c#] Benefits of using the conditional ?: (ternary) operator

Examples related to c#

Examples related to conditional-operator