A language that also supports inheritance or subtyping is classified as object-oriented.
[1] Even though object-oriented seems like a superset of object-based, they are used as mutually exclusive alternatives, rather than overlapping.
[citation needed] Examples of strictly object-based languages – supporting an object feature but not inheritance or subtyping – are early versions of Ada,[2] Visual Basic 6 (VB6), and Fortran 90.
Some classify prototype-based programming as object-based even though it supports inheritance and subtyping albeit not via a class concept.
A commonly used language with prototype-based programming support is JavaScript;