the speed of ? operator vs. the if statement

[DavidP]

Is there any difference between the speed of the ? operator and the if statement? ex:

int myint;
cin >> myint;
(myint == 5) ? cout << 'a' : cout << 'b';

vs.

int myint;
cin >> myint;
if(myint == 5) cout << 'a';
else cout << 'b';

so is there any speed difference? is the ? operator any faster?

[Prelude]

>is the ? operator any faster?
Yes, the ternary ?: operator can be faster. But since a decent compiler will optimize away the gains of ?: over if..else you should only use the ternary operator when there is a signifigant gain in readability.

-Prelude

[Justin W]

Of course, the true power of ? : is the fact that it is an operator. It can be evaluated by the "true" expression. For instance:

printf("You have %d item%s.\n", n, n==1 ? "" : "s"); 

is equivalent to:

printf("You have %d item", n);
if(n>1)
 {
 printf("s");
 }
printf(".\n"); 

You've saved 3 lines. There are really a lot of instances where treating it as an operator can really save your beacon.

-Justin

[Brian]

Originally posted by Justin W

printf("You have %d item%s.\n", n, n==1 ? "" : "s"); 

is equivalent to:

printf("You have %d item", n);
if(n>1)
 {
 printf("s");
 }
printf(".\n"); 

You've saved 3 lines. There are really a lot of instances where treating it as an operator can really save your beacon.

-Justin

You could do:

if(n>1)  printf("s\n");

[Justin W]

[possible misunderstanding]Not if you want a new line (and period) after either one, but not two for any given one.[/pm]

Unless you mean I didn't need the braces, which I didn't but just did 'cause I didn't want to step on most people's style. Save two or three lines depending upon if you use:
if(...)
statement

or
if(...) statement.