Question

I am asking this question considering the performance of script. Knowing that PHP arrays don’t perform very well, I am wandering which way is the best to go down when in this sort of situations.

Suppose if $x equals to a or b or c or d we need action_a() to execute and if not action_b() to execute..

We can either implement this with || operator as follows;

if($x == 'a' || $x == 'b' || $x == 'c' || $x == 'd'){
       action_a();
}else{
       action_b();
}

Or we can implement this using in_array() as follows;

if(in_array($x,array('a','b','c','d'))){
       action_a();
}else{
       action_b();
}

What I would like to know is which of these two options would perform well:

1. when the number of possible values for $x are high?

2. when the number of possible values for $x are low?

Answer 1

Write a benchmark script.

In general though, which variant to pick should hardly ever depend on performance. Especially in super trivial cases where your input data is very very small (say <10).

This most important criteria is always readability.

Only start optimizing code when there is an undeniable performance problem.

Premature optimization is the root of all evil.