Which is Faster and better, Switch Case or if else if?

Question

Which is the better and fastest methods : if or switch ?

if(x==1){   echo "hi"; } else if (x==2){   echo "bye"; }  switch(x){   case 1     ...   break;   default; }  

Answer 1

Your first example is simply wrong. You need elseif instead of just else.

If you use if..elseif... or switch is mainly a matter of preference. The performance is the same.

However, if all your conditions are of the type x == value with x being the same in every condition, switch usually makes sense. I'd also only use switch if there are more than e.g. two conditions.

A case where switch actually gives you a performance advantage is if the variable part is a function call:

switch(some_func()) {     case 1: ... break;     case 2: ... break; } 

Then some_func() is only called once while with

if(some_func() == 1) {} elseif(some_func() == 2) {} 

it would be called twice - including possible side-effects of the function call happening twice. However, you could always use $res = some_func(); and then use $res in your if conditions - so you can avoid this problem alltogether.

A case where you cannot use switch at all is when you have more complex conditions - switch only works for x == y with y being a constant value.