#define and const differences

Question

What is better in C and C++ to define constants? What are advantages of each method?

#define PI 3.14
or
const double PI 3.14

Answer 1

#define is a preprocessor directive. Things defined by #define are replaced by the preprocessor before compilation begins.

const variables are actual variables like other normal variable.

The big advantage of const over #define is type checking. We can also have poitners to const varaibles, we can pass them around, typecast them and any other thing that can be done with a normal variable.

And also #define replaces some text in program

Any how I would say const would better if you go with type checking (pointers and data types) and #define if you want to replace content , and have fast replacement of const's .