Properties can usually be changed, added, and deleted, but some are read only.
for...in statement loops through the properties of an object.
The block of code inside of the
for...in loop will be executed once for each property.
Looping through the properties of an object:
delete keyword deletes a property from an object:
delete keyword deletes both the value of the property and the property itself.
After deletion, the property cannot be used before it is added back again.
delete operator is designed to be used on object properties. It has no effect on
variables or functions.
properties. It can crash your application.
All properties have a name. In addition they also have a value.
The value is one of the property's attributes.
Other attributes are: enumerable, configurable, and writable.
These attributes define how the property can be accessed (is it readable?, is it writable?)
( ECMAScript 5 has methods for both getting and setting all property attributes)
delete keyword does not delete inherited properties, but if you delete a
prototype property, it will affect all objects
inherited from the prototype.