Why is Jshint saying “variable already defined” in this if statement?

Question

I have this code:

 if ( something is true ) {
        var someVar = true;
    } else {
       var someVar = false;
    }

JsHint is saying that

Answer 1

You shouldn't put var declarations in such places. Put the var declaration before the if, and then just set "someVar" to a value.

Indeed, here you don't need an if statement at all:

var someVar = !!(something);

will do the same thing. (The double application of ! ensures that "someVar" is set to either true or false, based on the "truthiness" of something.)