Below are some important difference between C , C++ AND OBJECTIVE-C

1. C is a procedural language. C++ is procedural as well as object oriented programming language. Objective-C is a general-purpose, high-level, object-oriented programming language.
2. In C, importance is given to the steps or procedure of the program. C++ focuses on data. Objective-c focuses on Both( function & Data).
3. Due to data hiding feature of OOP the data is secured in C++ and Objective-C. But in C the data is not secured..
4. C is low level programming language. C++ have features of both low level programming and high level programming language. Objective-C is a high level programming language.
5. Functions are building blocks of C therefore it is function-driven programming language. Both C and Objective-C are object driven programming languages.
6. Namespaces are present in C++. Namespaces are absent in C.
7. File name extension For C - .h, .c For Objective-C - .h, .m, .mm For C++ - .h, .hh, .cpp, .hpp, .cxx, .c++
8. In C programming language - Functions can be declared at the point of use. Objective-C - Totally class-based so function are declared in the classes.C++ - Functions must be prototyped before main.
9. In C and C++ header files need to be included, but there is no need to include header files in Objective-C.
10. C does not allow inheritance. C++ allows multiple inheritance but Objective-C doesn’t.
11. There is no concept of classes in C programming language. Declaration of classes is different in C++ and Objective-C.
12. In C++ methods look like C functions. In Objective-C methods look like Smalltalk methods.