Weird Calcul Error ?

cdrik6

Here is my program:

size(300,300); background(255); fill(0);

float a, b;

a = 575 * 2 / 100; b = 575 / 100 * 2;

text(str(a),10,20); text(str(b),100,20); println(a); println(b);

I should read 11.5 and 11.5, but i read 11 and 10. I guess a rounding using "/100", but why i just want to divide by 100. I guess something very simple behind that weird calcul error, but i can't find it !

Thank you

GoToLoop

https://forum.Processing.org/two/discussion/13417/problem-with-making-a-window-size-scale

koogs

Integer division, it's an FAQ

GoToLoop

It shoulda been in the / division operator's reference itself: X(
https://Processing.org/reference/divide.html

cdrik6

Sorry, i can imagine it is a FAQ, as it is very simple and basic point, and the reference of /divide on processing.org says nothing about that.

ok, so we just need to add a ".", it works, but i still find that strange, looks like a specificity of JAVA and C... why not. I am worried, i need to check all my old programs !

cdrik6

Thank you wasted hours on that!

GoToLoop

Just for completeness' sake, suffixing any number literal w/ f or d also forces it to become "fractional": 575 * 2 / 100f; ;)

Also any literal using scientific notation is automatically fractional too: 575 * 2 / 1e2; :-B

GoToLoop

P.S.: Learn how to format code for the forum too: B-)
https://forum.Processing.org/two/discussion/8045/how-to-format-code-and-text

cdrik6

Yes, got it, will use the tags so far, thanks

asimes

You also can use 100.0 instead of 100f