Which one is more efficient in terms of memory usage and instruction cycle if or for or switch

Question

please need

Answer 1

Between an if and a switch the switch probably wins.
I'm gonna ignore the for cause it's unrelated to these 2.

A switch uses a jump table or a binary search depending on the cases.
Cases like 0, 1, 2, 3 usually uses a jump table while if the cases are more random it'll use a binary search method.

An if/if else on the other hand checks every case 1 by 1 from top to bottom in both cases. Even with -O3. At least in my test cases.

Answer 2

Depends purpose of use.
If - in case single condition check.
Switch - in case you depend upon variable which takes multiple values.
For - if you want run set of instructions for certain number of times....

Hope this helps...!!!