expando

A property added to an object at run-time.

Noun

  1. A property added to an object at run-time.
    • Because JavaScript objects are not constrained to predefined interfaces as they are with .NET objects, you can set expando properties on any object. - 2009, Ted Pattison, Daniel Larson, Inside Microsoft Windows...
    • I talk more about expandos in Chapter 10. This means that you can arbitrarily add new properties to an object whenever you want. - 2010, Alexei White, JavaScript Programmer's Reference:

Origin

Perhaps a short form of expandable object.

Forms

expandos

Related

duck typing