Question about Logical Operation && without an if comparison ?

[Agent86]

I know the reference and book does not mention this but curious how it works for assignment instead of comparison. 

Can this even be done as intended ? 

For example:

extern bool      chart_period=true; //
extern bool      macdm1=false;
extern bool      macdm5=false;
extern bool      macdm15=false;
extern bool      macdh1=false;
extern bool      macdh4=false;
extern bool      macdd1=false;

string selections;


void selection()  //perhaps better for switch and case. 
   {
   if(chart_period && !macdm1 && !macdm5 && !macdm15 && !macdh1 && !macdh4 && !macdd1)
   selections="histo()";
   if(chart_period && macdm1 && !macdm5 && !macdm15 && !macdh1 && !macdh4 && !macdd1)
   selections="histo() && histo_M1()";
   if(chart_period && macdm1 && macdm5 && !macdm15 && !macdh1 && !macdh4 && !macdd1)
   selections="histo() && histo_M1() && histo_M5()";
   
   } 

These are bools in the comparisons. Not sure how to convert back to use for a comparison. 

Or if I should be using "bool selections" instead but I'm not sure how Logical Operation && views this without "if" ?

For example instead:

extern bool      chart_period=true; //
extern bool      macdm1=false;
extern bool      macdm5=false;
extern bool      macdm15=false;
extern bool      macdh1=false;
extern bool      macdh4=false;
extern bool      macdd1=false;

bool selections;

void selection()  //perhaps better for switch and case. 
   {
   if(chart_period && !macdm1 && !macdm5 && !macdm15 && !macdh1 && !macdh4 && !macdd1)
   selections=histo();
   if(chart_period && macdm1 && !macdm5 && !macdm15 && !macdh1 && !macdh4 && !macdd1)
   selections=histo() && histo_M1();
   if(chart_period && macdm1 && macdm5 && !macdm15 && !macdh1 && !macdh4 && !macdd1)
   selections=histo() && histo_M1() && histo_M5();
   

Is the && use even a valid option ? and if so what is the assignment if it can even be used like this. 

I know the references and book only show examples of if(&&) comparisons and I understand it's used that way but never considered if possible to use in an assignment if it can even be done. 

Please advise and educate me on this please. 
Thanks

[William Roeder]

Agent86: Or if I should be using "bool selections" instead but I'm not sure how Logical Oeration && views this witout "if" ?

If statement is irrelevant. if(bool) is the same as bool isSel=bool; if(isSel);.
          Increase Order after stoploss - MQL4 programming forum #1.3 (2017)

You should be able to read your code out loud and have it make sense. You would never write if( (2+2 == 4) == true) would you? if(2+2 == 4) is sufficient. So don't write if(bool == true), just use if(bool) or if(!bool). Code becomes self documenting when you use meaningful variable names, like bool isLongEnabled where as Long_Entry sounds like a trigger price or a ticket number and “if long entry” is an incomplete sentence.

[Agent86]

William Roeder #:

If statement is irrelevant. if(bool) is the same as bool isSel=bool; if(isSel);.
          Increase Order after stoploss - MQL4 programming forum #1.3 (2017)

You should be able to read your code out loud and have it make sense. You would never write if( (2+2 == 4) == true) would you? if(2+2 == 4) is sufficient. So don't write if(bool == true), just use if(bool) or if(!bool). Code becomes self documenting when you use meaningful variable names, like bool isLongEnabled where as Long_Entry sounds like a trigger price or a ticket number and “if long entry” is an incomplete sentence.

Yes, I seem to be going in circles and/or working myself in a corner.  

This code was based on my idea of multiple selections
https://www.mql5.com/en/forum/451149


I thought I might select properties and then when each property is true to assign the proper indicator or bool comparison to that. 

Such as selections = bool && bool;  or selections = bool && bool && bool

if(selections) code
if(!selections) code

This way instead of changing the comparison I could change it dynamically from the properties by selecting true or false etc. 

I couldn't think of anything else to make a dynamically changed comparison.

Thanks for the replies. 

 

[Agent86]

I'm confusing myself. 

What data type can be used as literal text as if I were typing the function name or variable name into the comparison manually ?

I thought a string might do this or to assign a variable with the same typed text but I see now this is not as I intended it.