A property, in some object-oriented programming languages, is a special sort of class member, intermediate in functionality between a field (or data member) and a method. The syntax for reading and writing of properties is like for fields, but property reads and writes are (usually) translated to 'getter' and 'setter' method calls. The field-like syntax is easier to read and write than many method calls,^{[citation needed]} yet the interposition of method calls "under the hood" allows for data validation, active updating (e.g., of GUI elements), or implementation of what may be called "read-only fields".

Programming languages that support properties include ActionScript 3, C#, D, Delphi/Free Pascal, eC, F#, Kotlin, JavaScript, Objective-C 2.0, Python, Scala, Swift, Lua, and Visual Basic.

Some object-oriented languages, such as Java and C++, do not support properties, requiring the programmer to define a pair of accessor and mutator methods instead.^{[citation needed]}

Oberon-2 provides an alternative mechanism using object variable visibility flags.^{[citation needed]}

Other languages designed for the Java Virtual Machine, such as Groovy, natively support properties.

While C++ does not have first class properties, they can be emulated with operator overloading.

Also note that some C++ compilers support first class properties as language extensions.^{[citation needed]}

In many object oriented languages properties are implemented as a pair of accessor/mutator methods, but accessed using the same syntax as for public fields. Omitting a method from the pair yields a read-only or an uncommon write-only property.