Advantages of OOP has the following advantages over conventional approaches: OOP provides a clear modular structure for programs which makes it good for defining abstract data-types where implementation details are hidden and the unit has a clearly defined interface. OOP makes it easy to maintain and modify existing code as new objects can be created with small differences to existing ones. OOP provides a good framework for code libraries where supplied software components can be easily adapted and modified by the programmer. This is particularly useful for developing graphical user interfaces. Concepts of OOP: Objects which included classes, data abstraction and encapsulation, inheritance, polymorphism.
Purely in terms of total instruction path length, a program coded in an imperative style, without using any subroutines at all, would have the lowest count. However, the binary size of such a program might be larger than the same program coded using subroutines (as in functional and procedural programming) and would reference more "non-local" physical instructions that may increase cache misses and increase instruction fetch overhead in modern processors.

The paradigms that use subroutines extensively (including functional, procedural and object-oriented) and do not also use significant in-lining (via compiler optimizations) will, consequently, use a greater percentage of total resources on the subroutine linkages themselves. Object oriented programs that do not deliberately alter program state directly, instead using mutator methods (or "setters") to encapsulate these state changes, will, as a direct consequence, have a greater overhead. This is due to the fact that message passing is essentially a subroutine call, but with three more additional overheads: dynamic memory allocation, parameter copying and dynamic dispatch. Obtaining memory from the heap and