Evaluation of Preprocessor Directive

[caradoc]

If I have #define defined as
#define dividefunc(a,b) a/b

and have a function call as
dividefun(x+2,y+3);

Suppose x=13 and y=2
How will the #define gets evaluated
Will it get substituted as
dividefun(13+2,2+2) which is equal to
dividefun(15,4)
and then get divided as 15/4 =4
or
will it get evaluated as
dividefun(x+2,y+2)
x+2/y+2 which is equal to
13+3/2+2 which becomes 13+1+2=16

Kindly let me know how the evaluation takes place

[ashlee]

It will get evaluated as
dividefun(x+2,y+2)
x+2/y+2 which is equal to
13+3/2+2 which becomes 13+1+2=16

This is because whenever a Preprocessor Directive is called the values given in parameters are substituted as such in the calling directive and then only operation takes place.