数组的strpos

Question

Let's say I have 90 'indexes' in my array and I have a function which checks if that value exists in that array, would it be faster if i used strpos with a String instead?

Instead of using in_array() to

$data = array('John','Mary','Steven');

It will be

$data = 'John.Mary.Steven';

then I'll just strpos() on that String?

Answer 1

Without bothering to profile it, I'd say that imploding to a string followed by strpos would be slower than PHP's built-in in_array() function.... because you're adding all the overhead of converting the entire array (all 90 elements) to a string before you can even use strpos(). Premature Micro-optimisation isn't a good idea, unless you really need it, and then you should test your ideas.

EDIT

If you're using your own function instead of in_array(), it probably is slower, but raises the question "why"?