Is c language a platform dependent language?

Answer 1

Definitely no, it can be used on Windows, Linux, Mac OS X, BSD, Solaris, ReactOS, and almost every single other OS, and it can be used to compile programs for x86, x64, ARM, loongson, PowerPC and most other CPU architectures.

That is incorrect. The C language specification is indeed platform-dependent, since the specifications contains numerous ambiguities (both intentional and unintentional) where the choice of proper behavior of the program is left to the C compiler or platform to decide.

C is a highly portable language, meaning that the supporting libraries and functions are widely available and there is general agreement on most of the C spec as to what proper behavior is. But, it is NOT platform independent.

As someone who has ported code between numerous hardware and OS architectures, there are VERY SIGNIFICANT differences between them that are exposed in C. An excellent way to see that C is platform-dependent is to look at a large C program (any of the larger GNU programs is a good idea). The code will be filled with #ifdef sections, which are the definition of platform-dependent.