JavaScript - which If Else condition should I use?

There are different methods to use condition statements

1. method:

   var x = 3,
       y;
   
       if (x == 4) y = 1;
       else if (x == 3) y = 2;
       else y = 3;
   
   alert(y);
   

2. method:

var x = 3,
    y = x == 4 ? 1 : x == 3 ? 2 : 3;

alert(y);

3. method:

var x = 3,
    y = x == 4 && 1 || x == 3 && 2 || 3;

alert(y);

My question now: Which method should I use? And why?