difference between global variable and #define.

#define YES 1 —->is syablic parameter.

const int yes=1—> Global declartion
Ex:

Take this example to #define GREEN G

#define statement inform to Complier YES as 1

You have different colours. you have to use colour name in your program many place. Each time you have to type each colour name, Its difficult to do that . So we are using #define statement to solve this probelm. Here we are declaring GREEN as G. So if u type G in your program its equal to GREEN.

So as per your question YES as an 1.

cons int yes=1 is static value we can not change the value.

one week have 7 days this is const. So we can declare weekdays as global variable. so

cons int weekdays=7;

I hope your doubt is clear now..
Thanks in advance.