c++ - Why would someone use #define to define constants?

Question

It's simple question but why would someone use #define to define constants?

What's the difference between

#define sum 1 and const int sum = 1;

Answer 1

#define has many different applications, but your question seems to be about one specific application: defining named constants.

In C++ there's rarely a reason to use #define to define named constants.

#define is normally widely used in C code, since C language is significantly different from C++ when it comes to defining constants. In short, const int objects are not constants in C, which means that in C the primary way to define a true constant is to use #define. (Also, for int constants one can use enums).