how am i failing to do a simple division math problem?

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hi,

i always read that double has fractional capability, so i have tried a simple 5/3 problem, but i'm getting 1.0

int  x = 5;
int y = 3;
double answer;

answer = (x/y);
Print (answer);

any help on how can i get the actual 1.6?

thanks in advance

 
zelda_lee:

hi,

i always read that double has fractional capability, so i have tried a simple 5/3 problem, but i'm getting 1.0

any help on how can i get the actual 1.6?

thanks in advance

Yes, so do not use an int.

 
The math is being done in Int space because that's the type of memory you used to store the original numbers.  This is a common compiler issue in many programming languages.  Try changing at least X to a double and see what happens...
 
Shalem Loritsch #:
The math is being done in Int space because that's the type of memory you used to store the original numbers.  This is a common compiler issue in many programming languages.  Try changing at least X to a double and see what happens...

yes it works as it should if both inputs are double

thanks

 
zelda_lee: so i have tried a simple 5/3 problem, but i'm getting 1.0

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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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;


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