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 su

Answer 1

Always try to use "const int", rather than #define.

Use #define, only when your preprocessor code might be read by another tool, and it's easier for it to go with the preprocessor, rather than to parse the language.

Also it's the only way to define something to be checked later by #if/#else/#endif