[Drixevel]

Not entirely convinced by the performance values so I figured I'd post here for a quick answer.

Would this for example...

new value;
if (value == 1)
{
	//Do stuff
}
else if (value == 2)
{
	//Do other stuff
}

Be a bit more effective in terms of performance or this...

new value;
switch (value)
{
	case 1:
		{
			//Do stuff
		}
	case 2:
		{
			//Do other stuff
		}
}

Purely, which one runs better or does it not matter? I like Switch statements a lot better.

Cheers,
- Jack

[bl4nk]

It's really up to the compiler, and I'm not an expert on how that works with SourcePawn. Sometimes an if/else/elseif statement could be just as fast as when using a switch, but most other times the switch would be faster. In the specific case you posted, there probably wouldn't be a difference in which you used.

[Impact123]

Switch is said to be faster (AMX), but the difference is very very small, use what fits your style the best.
You should rather spent your time optimizing the code inside the statement you use.
Here are some tests, each function is called 500 times.

Results

If function

Benchmark: 0.000012 seconds, 0.012760 milliseconds
Benchmark: 0.000004 seconds, 0.004374 milliseconds
Benchmark: 0.000010 seconds, 0.010937 milliseconds
Benchmark: 0.000004 seconds, 0.004739 milliseconds
Benchmark: 0.000004 seconds, 0.004374 milliseconds

Switch function

Benchmark: 0.000011 seconds, 0.011666 milliseconds
Benchmark: 0.000003 seconds, 0.003645 milliseconds
Benchmark: 0.000008 seconds, 0.008749 milliseconds
Benchmark: 0.000004 seconds, 0.004010 milliseconds
Benchmark: 0.000003 seconds, 0.003645 milliseconds

Offtopic

I like to write optimized code myself, but you should only do this if you know what effect your "optimisation" has, and only if it's worth it.

For example

PHP Code:

if (GetConvarBool(...) && localVar) 


Should be replaced like this because the native call is slower

PHP Code:

if (localVar && GetConvarBool(...)) 


[friagram]

If you are doing finite comparisons, should probly use switch. It's more human-readable anyway.

[Drixevel]

Thank you for the tips guys. I'm trying to optimize my plugins to run a lot smoother than they do now. I like using switch statements because it's just overall easier to manage.

[MasterOfTheXP]

Another situation in which to pretty much always use switch statements instead of if statements are lists like these, where the repetitiveness speaks for itself:

PHP Code:

if (i == 1 || i == 2 || i == 3 || i == 4 || i == 5) return; 


PHP Code:

switch (i) { case 1, 2, 3, 4, 5: return; } 


[Powerlord]

Generally, switch is more efficient than if/elseif/else because switch can be implemented using a jump table. I don't know if the SourcePawn compiler does this or not.

[necavi]

At least in C they can be implemented any number of ways by the compiler...a series of if/else type structures, a jump table, or probably one or two others that I'm forgetting, but I believe that pawn uses jump tables.

[sdz]

In my opinion and experiences, I prefer switch for a few reasons:

• Looks alot better then else if else if else if
• case 69:
• Just alot easier to write