var myJSONObject = {"ircEvent": "PRIVMSG", "method": "newURI", "regex": "^http://.*"};

var myJSONObject = {"ircEvent": "PRIVMSG", "method": "newURI"};

delete myJSONObject.regex;
// or,
delete myJSONObject['regex'];
// or,
var prop = "regex";
delete myJSONObject[prop];

var myJSONObject = {"ircEvent": "PRIVMSG", "method": "newURI", "regex": "^http://.*"};

delete myJSONObject.regex;

alert ( myJSONObject.regex);

var obj = {
     field: 1
 };
 delete obj.field;

var obj = {
     field: 1
 };
 obj.field = undefined;

console.log('* -> "Takes prototype inheritance into consideration, that means it lookups all over prototype chain too."');

 console.log(obj.field === undefined, 'obj.field === undefined', 'You get "undefined" value when querying for "field" in object-hashmap. *');

 console.log(obj["field"] === undefined, 'obj["field"] === undefined', 'Just another way to query (equivalent). *');

 console.log(typeof obj.field === "undefined", 'typeof obj.field === "undefined"', 'Get the value attached to "field" key, and check it's type is "undefined". *');

 console.log(! ("field" in obj), '! ("field" in obj)', 'This statement returns true if "field" key exists in the hashmap. False otherwise. *');

 console.log(obj.hasOwnProperty("field"), 'obj.hasOwnProperty("field")', 'This statement returns true if 'field' key exists in the hashmap. The ONLY way NOT to lookup for property in the prototype chain!');
 //Object.keys().indexOf() is an overkill :)

 var counter = 0,
     key;
 for (key in obj) {
     counter++;
 }
 console.assert(counter === 0, 'counter === 0', '"field" is not iterated using "for .. in" loop. *');

var array = [1,2,3,4];
delete array[2];
//Expected result --> [1,2,4]
//Actual result   --> [1,2,null,4]

Array.prototype.remove = function(index){
    delete this[index];
    return this;
};
Array.prototype.clean = function(){
    var arr1 = this, arr2 = [];
    for(var a in arr1){
        if(arr1[a]&&arr1.hasOwnProperty(a)){
            arr2.push(arr1[a]);
        }
    }
    this.splice(0);
    for(var b in arr2){
        if(arr2.hasOwnProperty(b)){
            this.push(arr2[b]);
        }
    }
    return this;
};
var array = [1,2,3,4];
array.remove(2).clean();
// Result --> [1,2,4]

Array.prototype.remove = function(index){
  this.splice(index,1);
}

myJSONObject = {"ircEvent": "PRIVMSG", "method": "newURI", "regex": "^http://.*"};

console.log(Object.keys(myJSONObject));

["ircEvent", "method", "regex"]

delete myJSONObject["regex"];

["ircEvent", "method"]

myJSONObject["regex"] = null;
delete myJSONObject["regex"];

var regex = myJSONObject["regex"];

var myOtherObject = {};
myOtherObject["regex"] = myJSONObject["regex"];

delete regex; //False

myOtherObject["regex"] = null;
delete myOtherObject["regex"];

var myJSONObject =
{"ircEvent": "PRIVMSG", "method": "newURI", "regex": "^http://.*"};

_.pick(myJSONObject, "ircEvent", "method");
=> {"ircEvent": "PRIVMSG", "method": "newURI"};

var myJSONObject =
{"ircEvent": "PRIVMSG", "method": "newURI", "regex": "^http://.*"};

_.omit(myJSONObject, "regex");
=> {"ircEvent": "PRIVMSG", "method": "newURI"};

var obj = {"property":"value", "property2":"value"};

if (obj && obj.hasOwnProperty("property2")) {
  delete obj.property2;
} else {
  //error handling
}

//Inconsistent behavior if the same object is stored in an
//array or object and also somewhere else at the same time.
//Any inconsistency.

function my_delete (objectOrArray, index) {
    if (objectOrArray.splice) {
        objectOrArray.splice(index,1);
    } else {
        delete(objectOrArray[index]);
    }
}

var myJSONObject = {"ircEvent": "PRIVMSG", "method": "newURI", "regex": "^http://.*"};
delete myJSONObject.regex;
alert ( myJSONObject.regex);