Does declaring variables in a loop waste memory? [duplicate]

Consider this:

var i = 0;
var isEight = false;

while(true){
    if( i === 8) {
        isEight = true;
        break;
    }
    i++;
}

versus this:

var i = 0;

while(true){
    var isEight = false; // moved declaration inside 
    if( i === 8) {
        isEight = true;
        break;
    }
    i++;
}

The example is contrived but you get the idea. How does Javascript respond when the declaration of isEight is brought inside the loop?

Does a new memory space get allocated every time that line runs? Will this be a serious issue if the loop runs many many times?

Update: Since alex pointed out, what about using let instead of var in this case.