Program Structure

[[Deleted]]

I'm just starting to learn this stuff, and looking at some of the EAs my first question is program structure. What goes first, last, etc. The particular EA i'm looking at starts with:

//---- input parameters
extern int x1 = 135;
extern int x2 = 127;
extern int x3 = 16;
extern int x4 = 93;

I can find out what the extern means, but the rest?

[Ray]

Do you have any prior programming experience?

if no

'MQL4 Language for Newbies. Introduction'

might help