Question

Here is my code snippet:

float ab(float);

and later

if(ab(temp)<ab(a[r][c]))
{ do something; }

where

float temp;a[6][6];

Now what really is this declaration float ab(float) and how it is used later?

Answer 1

It’s a function prototype. The function is called ab; it takes a float and returns a float. In the if statement, ab(...) is simply a call to that function.

To figure out what the function does, you’ll have to find its definition.