Object keys iteration with forEach

object-iteration-for-in.js

// iteration using for..in loop and hasOwnProperty
var Person = {
    name: 'mr smith',
    profession: 'dandy fella',
    age: 10000,

    reset: function() {
        for (var prop in this) {
            if (prop == 'reset' || !this.hasOwnProperty(prop)) {
                console.log("leave it alone", prop)
            } else {
                this[prop] = null
            }
        }
    }
}

object-iteration-foreach.js

// Iteration using forEach
var Person = {
    name: 'mr smith',
    profession: 'dandy fella',
    age: 10000,

    reset: function() {
        Object.keys(this).forEach(function(prop) {
        	if (prop != 'reset') {
        		this[prop] = null; // this now references Person 
        	}
        }, this) // this references Person
    }
}