efficiency issues

[dimitris]

Hi all,

 

I would like to ask about two programming techniques, regarding their efficiancy. First,

 

is there actually any difference between

 

<?php
function example() {
if (...) { ... $return_value = value1;}
else if (...) { ... $return_value = value2;}
else (...) { ... $return_value = value3;}
return $return_value;
}?>

 

and this one

 

<?php
function example() {
if (...) { ... return $value1;}
else if (...) { ... return $value2;}
else { ... return $value3;}
}?>

 

Secondly,

 

<?php
$sql = "SELECT ... FROM ... WHERE..."; //  or whatever query
$result = mysqli_query($sql) or die(mysqli_error());
?>

 

isn't it better this one?

 

<?php
$result = mysqli_query("SELECT ... FROM ... WHERE...") or die(mysqli_error());
?>

 

I've seen the first ones in both cases used and was wondering if the second ones are improvements or not... Is there any point in trying to make the code as efficient as possible in PHP, or is it a waste of time? I've being used to think like this since I'm coming from a C/C++ background but don't know if it's worth going to the bottom in PHP, does it really make any difference? Sorry if my questions are naive...

 

dimitris

[lemmin]

For your first one: Yes, there is a difference. You are allocating more space in memory for the first code sample because you are setting a variable, the second one is slightly more efficient.

 

For your second one: Yes the second one is more efficient (in the same way as your first question), but for debugging purposes, it is nice to be able to see what your sql string actually is, especially when it is being created dynamically. I personally only use the first way when debugging.

[madk]

9/10 times I just optimize using a simple time measurement as most of my scripts are not memory intensive.  If you are worried about memory usage in a long script you can always free up memory after you are done using a variable.