floats being saved as 0 after calculation

Question

Very confused here, I have this code:

float temp = (1/10)*100;
Label.Text = Convert.ToString(temp);

for some reason my temp variable is being saved as 0 which means my label text is changed to 0 when I'm expecting 10, I have the same issue when using doubles instead. What has gone wrong?

`float temp = (1/10.0)*100`; 1/10 integer division -> == 0 * 100 == 0 — Patrick Artner, Jan 13 '18 at 16:09
Please read this- https://stackoverflow.com/questions/11519743/why-is-the-f-required-when-declaring-floats. By the way you have done zero efforts to search for it. — Souvik Ghosh, Jan 13 '18 at 16:12
Yep, problem is `1/10` is two integers being divided. Simple fix is `1.0f / 10.0f` which explicitly declares both numbers as floats so there's no surprises. — Khauri, Jan 13 '18 at 16:12

user8303157 · Accepted Answer · 2018-01-13T16:22:14.953

0

Since 1, 10 and 100 are all integer values, the division is also an int value, rounded down. In this case 1/10 = 0 so (1/10)*100 = 0 If you do not want this try using floats:

(1.0f/10)*100

In case you're working with integer variables you have to convert them first. This can be achieved by casting, like so:

int a=1;
...
float b = ((float) a)/10; // b will be 0.1

Another quick way of doing this in a line with multiple operations is multiplying by 1.0f:

int x = 100;
float c = (a*1.0f)/x;  // c will be 0.01f

edited Jan 13 '18 at 16:22

answered Jan 13 '18 at 16:13

user8303157

31
2

If I was using variables instead of just the numeric values I'm assuming I'd just need to convert them all to floats first? – Andrew Neate Jan 13 '18 at 16:14
1

@AndrewNeate yes, I updated the answer – user8303157 Jan 13 '18 at 16:22

floats being saved as 0 after calculation

1 Answers1