Some simple examples to help grok scope in JS in terms of object literals, functions, prototypes and inheritance

GrokJSScope.js

// Grok JS Scope for Object Literals in Various Uses
var name = 'Keith Window';

var obj = {
    name: 'Keith Object',
    getObjName: function(){
        return this.name;
    },
    getWindowName: function(){
        return name;
    }
};

console.log("-- Grok JS Scope for Object Literals in Various Uses --");
console.log(obj.getWindowName());
console.log(obj.getObjName());

console.log("--------FUNCTION SCOPE------------");
(function fn(o){
    var name = 'Keith Self-executing Function';
    console.log("Inside a self-executing function...");
    console.log(name);      // Get name from function scope
    console.log(o.getWindowName());     // Window scope
    console.log(o.getObjName());        // Object scope
}(obj));

console.log("--------------------");
function func(o){
    var name = 'Keith Plain Old Function';
    console.log("Inside a plain old function...");
    console.log(name);      // Get name from function scope
    console.log(o.getWindowName());     // Window scope
    console.log(o.getObjName());        // Object scope
}
func(obj);

console.log("--------------------");
var me = new func({
    name: 'Keith Object Literal inside New Instance',
    getObjName: function(){
        return this.name;
    },
    getWindowName: function(){
        return name;
    }
});

console.log("---------INSTANCE AND CLASS SCOPE-----------");
function _Class(config){
    // Private
    var name = 'Keith Class';
    
    // Public
    this.name = (config.name || "Noname McGee" ) + ' Instance' ;
    this.getClassName = config.getClassName || function(){
        return name;
    }
    this.getInstanceName = config.getInstanceName || function(){
        return this.name;
    }
}
var keith = new _Class({
    name: 'Keith'
});
console.log(keith.getClassName());
console.log(keith.getInstanceName());

var keith2 = new _Class({
    name: 'Keith2',
    getInstanceName: function(){
        return this.name;
    }
});
console.log(keith2.getInstanceName());


console.log("---------PROTOTYPE SCOPE-----------");
_Class.prototype.name = 'Keith Prototype';
_Class.prototype.getWindowName = function(){
    console.log(">Evoked from prototype");
    return name;        // Window
}
_Class.prototype.getPrototypeName = function(){
    console.log(">Evoked from prototype");
    return _Class.prototype.name;
}
_Class.prototype.getInstanceName = function(){
    console.log(">Evoked from prototype");
    return this.name;
}
_Class.prototype.getClassName = function(){
    console.log(">Evoked from prototype");
    return new _Class({}).getClassName();
}

// Delete the instance vars first so JS will look to the prototyle
delete keith.getClassName;
delete keith.getInstanceName;
console.log(keith.getWindowName());
console.log(keith.getPrototypeName());
console.log(keith.getClassName());
console.log(keith.getInstanceName());

console.log("---------PROTOTYPAL INHERITANCE SCOPE-----------");
function Child(config){
    this.name = config.name || 'Baby';
    this.getInstanceName = function(){
        return this.name;
    }
}
Child.prototype = new _Class({ name: 'Daddy Keith' });  // You can't access this from Child

var babykakes = new Child({ name: 'Baby Keith' });
console.log(babykakes.getWindowName());
console.log(babykakes.getPrototypeName());
console.log(babykakes.getClassName());
console.log(babykakes.getInstanceName());