[javascript] How do I remove a key from a JavaScript object?

Let's say we have an object with this format:

var thisIsObject= {
   'Cow' : 'Moo',
   'Cat' : 'Meow',
   'Dog' : 'Bark'
};

I wanted to do a function that removes by key:

removeFromObjectByKey('Cow');

If you are using Underscore.js or Lodash, there is a function 'omit' that will do it.
http://underscorejs.org/#omit

var thisIsObject= {
    'Cow' : 'Moo',
    'Cat' : 'Meow',
    'Dog' : 'Bark'
};
_.omit(thisIsObject,'Cow'); //It will return a new object

=> {'Cat' : 'Meow', 'Dog' : 'Bark'}  //result

If you want to modify the current object, assign the returning object to the current object.

thisIsObject = _.omit(thisIsObject,'Cow');

With pure JavaScript, use:

delete thisIsObject['Cow'];

Another option with pure JavaScript.

thisIsObject.cow = undefined;

thisIsObject = JSON.parse(JSON.stringify(thisIsObject ));

It's as easy as:

delete object.keyname;

or

delete object["keyname"];