Question

While I was reading about JavaScript hoisting, I tried the following. I am not sure why the first one and second one output differently. (I am not even sure that this is related to hoisting).

var me = 1;
function findme(){
   if(me){
    console.log( me );//output 1
    }
  console.log( me ); //output 1
}
findme();

However the following outputs undefined:

var me = 1;
function findme(){
 if(me){
    var me = 100;
    console.log(me); 
    }
  console.log(me); 
}
findme();
// undefined

Answer 1

Variable declarations get hoisted to the top of every function, but the value assignments stay where they are. So the second example is run like this:

var me = 1;
function findme () {
    var me;  // (typeof me === 'undefined') evaluates to true
    if (me) { // evaluates to false, doesn't get executed
        me = 100;
        console.log(me); 
    }
    console.log(me); 
}
findme();