No, it does not affect your application at all. On the contrary, it helps with the overall maintenance of an application and is thus promoted and supported by ALL teachers around the globe.
Imagine you have to "adjust" another developer's application that has NO comments. He also has his own style of naming conventions for example say a command button, the norm is cmdMyButton, but he calls it ThisButtonHere. The enormous task to try and sift through OOP subs and declerations will drive you mad.
If there is however a comment below the naming of the button saying "Save Data with this button etc..", you will know exactly what to expect throughout the rest of the sub's code.:)
#define A 3// name a constant
long int booking_ID ; ...