Nested Function's Scope : An interesting thing to note about nested functions in javascript is that they have access to the parent functions variables and parameters. This is unlike variables defined at the global level

NestedFunctionScope.js

foo(1);

function foo(a){
    var b = 2;
    
    bar(3);
    
    function bar(c){
        //all parent variables are visible and editable from here
        console.log(a);
        console.log(b);
        console.log(c);
    }
}