Short JavaScript Quiz

Give the output of  the following and define the scope of variables

<script>


// a _____-scoped variable
var a=1;

// ______ scope
function one(){
    alert(a); 
}

// ______ scope
function two(a){
    alert(a);
}

// ______ scope
function three(){
  var a = 3;
  alert(a);
}

// Intermediate: 
Does javascript have a block scope ?
function four(){
    if(true){
        var a=4;
    }

    alert(a);
}


// Intermediate:  ______ ______ properties
function Five(){
    this.a = 5;
}


// Advanced: closure
var six = function(){
    var foo = 6;

    return function(){
        // javascript - "closure" means I have access to foo in here,
        // [ to be updated ]
        alert(foo);
    }
}()


// Advanced: __________ scope resolution
function Seven(){
  this.a = 7;
}

// [object].______ loses to [object].______ in the scope chain

Seven.prototype.a = -1; // ______ get reached, because __ is __ in the constructor above.

Seven.prototype.b = 8; // ______ get reached, even though __ is ___ set in the constructor.

one();

two(2);

three();

four();

alert(new Five().a);

six();

alert(new Seven().a);

alert(new Seven().b);

</script>
The best ever examples given by Triptych - on Stackoverflow.com
Source:
http://stackoverflow.com/questions/500431/javascript-variable-scope