Can I get a little help with EA which includes many functions?

Hello everyone. I am working on an EA and it's starting to contain a LOT of functions. I'd like to make a libray for these functions, (actually I have so many, I'm probably going to make 3 different library files to make things even more straightforward). Some of the functions need to share global variables with the main EA. I was going to simply create the library files an use them the standard way, but then I found out that I will need to include these files in the MT4 library folder when I want to run it, in other words, they don't compile into the EA. I don't want external files i have to make sure are there, I want everything compiled into just one EA. So I decided to go the #include "mylib.mqh" route. But I couldn't compile my library files without declaring the variables that are already declared in my main ea. Won't redeclaring them here reset them?

How best to do this?

If you have library functions that are general purpose and reusable, never share other variables - pass everything you need by parameter. This will save you lots of problems in the future.

It would be easier to simply have global variables than rewrite every single one of my functions, wouldnt it?

When you have a small number of libraries, yes, but when you start increasing the number of libraries, it's far easier to just pass parameters back and forth instead of having shared global variables.

Ok, I changed the functions around, at least for my first library--StatisticalLib.

However it appeaers that can't compile this as none of the functions are called?

Compiling 'StatisticalLib.mq4'...
Start function not found and cannot be run.
Function "Price" is not referenced and will be removed from exp-file
Function "RoundAsk" is not referenced and will be removed from exp-file
Function "RoundBid" is not referenced and will be removed from exp-file
Function "ThreeHourHi" is not referenced and will be removed from exp-file

don't compile mqh. just compile EA mq4 file that include those mqh. all lines in mqh will be appended to mq4 file

Can I call functions from one library in functions from a different library if they are both included in the EA code?

And how would I use a global variable across all libraries and my EA if I wanted to? Would I just declare the variable on each library and in the main EA on global scope?

Hi guys! I encounter similar issue as below.

Compiling 'Trade_P.mq4'...
Start function not found and cannot be run.
Function "TP_4H" is not referenced and will be removed from exp-file
Function "TP_1D" is not referenced and will be removed from exp-file


So i should not compile the mqh? Then why MT4 should generate these errors since it it not errros?

Why don't you have a Start() function? Every EA template from the wizard comes with one.


The other two messages are informative. The compiler is informing you of the situation in case it was an oversight. You can ignore or clean up the code.

Em...Sorry. I am referring to #include mqh

After i have done some test for coding, when i click the compile button for #include. It shows the errors. But when try running the EA after attached the #inclued <.......>, it fine.

So what is the reason why MT4 shows the errors?

I would not recommend using #include logic if you are a novice coder. It is a very useful and powerful way to organize code, but as your experience shows it can be tricky to use.

Em...understand. Yes, i am new to Mt4 coding. But i have experience of vba coding. So the logic is the same as MT4, the different is the format. That's the reason why i prefer to use #include to make my code clean and simple, and try to call the functions instead of writing repeated code.

So what is the reason why MT4 shows the errors? Just to ignore it. Then what if there is real errors.

Programming skill has very little to do with the language and a whole lot to do with methods used to code. It starts with analysis and ends with solid working code. What happens in between is what makes a programmer successful. Clean code is a worthwhile goal, but ultimately a proper working program is much more important. Usually the two go together ie. clean code will work better than a mess. But I have seen people get so wrapped up in making their code tight and modular and whatever buzzy concept is the flavour of the day, that they can't produce working code in a reasonable time frame.

You have to make a choice. There is a way to do what you want, but the way I would go about things is probably different than yours and the other readers of this thread.