Switch statement and type coercion

Question

I read in the 'Professional JavaScript for Web Developers' by Nicholas Zakas in p.78 of 3rd edition (last one I think):

The switch statement compares values using the identically equal operator, so no type coercion occurs (for example the string "10" is not equal to the number 10).

I made up some simple switch statement just to confirm and the result was different:

var num = "9";

switch (true) {
    case num < 0:
        alert("less than 0");
        break;

    case num >= 0 && num <10:
        alert("between 0 and 10");
        break;

    default:
        alert("False");

} 

https://jsfiddle.net/pbxyvjyf/

So, type coercion is done: the alert("between 0 and 10") is chosen. Have the rules changed or am I doing something wrong?

Answer 1

your case statements return a boolean so the type is correct

num >= 0 && num <10 - returns true or false

but if i would do this

switch (1) {
    case "1":
        console.log("never get here");
        break;

    case 1:
        console.log("but this works");
        break;

}