CODEWITHSUNDEEP
c++ternary-operator
Tony
Tony

Reputation: 373

"Do nothing" in the else-part of the ternary operator?

What's the standard line to add to the ternary operator in order to do nothing if the condition is not met?

Example:

int a = 0;
a > 10 ? a = 5 : /*do nothing*/;

Using a seems to do the trick, but I am wondering if there is a more generally accepted way.

Upvotes: 7

Views: 14915

Answers (5)

Sergey Kolesnik
Sergey Kolesnik

Reputation: 3640

Just for a sake of variety, but not recommending as it is very ambiguous.

void do_smth()
{}

bool a = true; // not necessarily 

a && (do_smth(), 0);

Upvotes: 0

Sam S
Sam S

Reputation: 336

You can also use a logical expression (though maybe confusing) in case you don't want to use an if statement.

a > 10 && a = 5

Upvotes: 4

HolyBlackCat
HolyBlackCat

Reputation: 96286

Another option:

a ? void(a = 0) : void();

What's good about this one is that it works even if you can't construct an instance of decltype(a = 0) to put into the 'do nothing' expression. (Which doesn't matter for primitive types anyway.)

Upvotes: 6

granmirupa
granmirupa

Reputation: 2790

You can do:

a > 10 ? a=5 : 0;

But, I would prefer:

if (a > 10) 
   a = 5;

Upvotes: 0

Helmut D
Helmut D

Reputation: 680

That will do it:

a = a > 10 ? 5 : a;

or simply:

if (a > 10) a = 5;

Upvotes: 21

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