eg:
#define a 10
'a' value is constant has always 10.
#define can be used before all functions or inside functions like usual variable declaration.
#include< stdio.h >
#define a 1
main( )
{
#define b 2
printf("%d %d", a,b);
}
not only used for define values but also define function.
#define f(a,b) a+b
this function will get two arguments a and b and return addition of them.
#include< stdio.h >
#define fn(a,b,c) a+(b*c)
main()
{
printf("%d",fn(1,2,3));
}
output:
7
