Difference Detween #define and Const

One is a preprocessor directive and one is a compiler directive

 

When you use const, the compiler will do appropriate checks during the compile time. So, it's better to use const instead of #define, wherever possible.

 

Also, #define gets substituted in the code by its value, thus increasing the size of executable. When you use const, this is not the case.

Next Recommended Reading const and readonly