// the object

var man = {

    hands: 2,

    legs: 2,

    heads: 1

};

// somewhere else in the code

// a method was added to all objects

if (typeof Object.prototype.clone = = = "undefined") {

    Object.prototype.clone = function () {};

}

// 1. for-in loop

for (var i in man) {

    if (man.hasOwnProperty(i)) { // filter

        console.log(i, ":", man[i]);

    }

}

/*

    result in the console

    hands : 2

    legs : 2

    heads : 1

*/

// 2. antipattern:

// for-in loop without checking hasOwnProperty()

for (var i in man) {

    console.log(i, ":", man[i]);

}

/*

    result in the console

    hands : 2

    legs : 2

    heads : 1

    clone: function()

*/

var i,

    hasOwn = Object.prototype.hasOwnProperty;

    for (i in man) {

        if (hasOwn.call(man, i)) { // filter

            console.log(i, ":", man[i]);

    }

}