simple cal problom,why

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  double a;
        a=1/5;
Alert(a);
why the result is 0
 
zdj229: why the result is 0

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Rare code issue

Fernando Carreiro, 2021.07.23 22:20

Please understand that dividing by 100 or dividing by 100.0 will give totally different results.

In the former, 100 is considered an Integer literal constant and so it will carry out integer division which will truncate the decimal values.

In the latter, 100.0 will be considered a floating-point literal constant and it will carry out floating-point division which will keep the decimal values.

This is the principal behind the problems you are having. So, to prevent this, either use a floating-point literal constant or typecast the variable into a (double).

Example:

Print( "90   / 100   = ", 90   / 100   );
Print( "90   / 100.0 = ", 90   / 100.0 );
Print( "90.0 / 100   = ", 90.0 / 100   );
Print( "90.0 / 100.0 = ", 90.0 / 100.0 );

2021.07.23 21:26:57.060 TestCopy EURUSD,H1: 90   / 100   = 0
2021.07.23 21:26:57.060 TestCopy EURUSD,H1: 90   / 100.0 = 0.9
2021.07.23 21:26:57.060 TestCopy EURUSD,H1: 90.0 / 100   = 0.9
2021.07.23 21:26:57.060 TestCopy EURUSD,H1: 90.0 / 100.0 = 0.9

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MT4 forcing doubles into int

Fernando Carreiro, 2022.03.23 17:53

Typecast them into floating point — Typecasting - Data Types - Language Basics - MQL4 Reference 

double Average = (double) Bars /          Found;
double Average =          Bars / (double) Found;
double Average = (double) Bars / (double) Found;


 
zdj229: why the result is 0

Of course, it does.
          On MT4 v434, division quotient don't give floating point values(Bug??) - MQL4 programming forum (2012)
          build 2504 & 2506 Bug - General - MQL5 programming forum - Page 2 #17 (2020)

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