delete

The delete operator can be used to remove a property from an object. It will remove a property from the object if it has one. It will not touch any of the objects in the prototype linkage. Removing a property from an object may allow a property from the prototype linkage to shine through: var stooge = {}; stooge.name = "fred"; if (typeof Object.beget !== 'function') { Object.beget = function(o) { var F = function() { }; F.prototype = o; return new F(); }; } var another_stooge = Object.beget(stooge); another_stooge.name = "jeff"; alert(another_stooge.name); //jeff delete another_stooge.name; alert(another_stooge.name); //fred