If block vs Switch-Case block

Question

Generally is there a performance difference between using an if block with many else ifs compared to a switch case block? Do some languages or style conventions prefer one over the other?

Specifically I am curious about Matlab, C, and C++

Answer 1

A switch can be optimized by the compiler, in some cases, into a lookup table and branch. This could be considerably faster than multiple if/else-ifs.

Answer 2

In C, the optimizer can turn a switch into a calculated jmp, so it can be faster. This is possible because you always switch on an integer constant.