JavaScript Performance switch (Integer) vs switch (String)

Question

I'm coming from C# and there it's a huge different between
A:

var stringVal = "1";
switch (stringVal)
{
    case "0" :
    break;
    case "1" :
    break;
}

and
B:

var intVal = 1;
switch (intVal)
{
    case 0 :
    break;
    case 1 :
    break;
}

B is much faster in C# (cause the String-Switch will converted to if-else-structure from the compiler).

Is it in JavaScript similar? (Of course there is just the number-type in JS)

And - for readability - if i want to use it with some enum-"equivalent" in JS (like described here http://stijndewitt.com/2014/01/26/enums-in-javascript/), is there a anyway performance-improvement when using

var caseEnum = {
    firstCase : 0,
    secCase : 1
}

var enumVal = caseEnum.secCase ;
switch (enumVal )
{
    case caseEnum.firstCase :
    break;
    case caseEnum.secCase :
    break;
}

?

(I know that i could do it with object literals, but the switch-statement with integer is more naturally for me)

Answer 1

I did a little incredible ugly Test on my own
( look at:https://jsfiddle.net/PutziSan/kzdwt8u2 )

and run the code on different browsers (results below), (all the browsers was updated on the latest version today - 03.01.2016)

by the way another hint, that edge and IE is just ridiculous.
The results are realy interesting, i guess.
(I know this sort of "tests" are not that accurate, but i think they can give a hint)

It seems, that switch with Integer is noticed from the compilers, but it has not that great impact.

chrome:

firefox:

edge:

IE: