cloud pasture
Hello, I am really new into C never had any other experience in coding but now as i started to study I have a course where we start with the language c.
So my task was to make a small calculation of transfering celsius from -40 degree to 70 into fahrenheit without using if and the steps to be +10 degree. For some reason here the multiplication -> ts+ 1* x * faktor isnt working how i want it to, anybody got a good source for me where to find a explanation for my problem?
barren cradle
9 / 5 does integer division, which means it rounds towards 0 and becomes 1
by the way, this would have been better in #1013104018739974194
cloud pasture
oh, so I would have to use float for my faktor there?
cloud pasture
by the way, this would have been better in <#1013104018739974194>
oh thank you was meant to go there didnt double check the chat
barren cradle
you would change the type of faktor to float or, better, double
and you'd use 9.0 instead of 9
cloud pasture
Ah okay thank you 🙌
barren cradle
no problem
slow zephyrBOT
@cloud pasture Has your question been resolved? If so, type !solved :)
barren cradle
maybe what I've written is a bit misleading
9.0 or 9. is a double literal
9.0f would be the float literal
but you should use double by default, not float
cloud pasture
also one more quesion, if i have a equation like in my code that is -40 + 2 * 10 * 9/5 + 32 do I have to make any () like in math so it doesnt mess anything up?
barren cradle
C has the normal precedence rules ("Punkt vor Strich")
and it's left associative, so 10 * 9 / 5 is the same as (10 * 9) / 5, not 10 * (9 / 5)
echo python
All german here?
Nice
🇩🇪
You could also write a function instead of using multiple times printf. But both works
barren cradle
also one more quesion, if i have a equation like in my code that is -40 + 2 * 10...
so to come back to this, () can matter: 10 * 9 / 5 is the same as 90 / 5, and 90 is divisible by 5 so that does what you'd expect.
But if you had written 9 / 5 * 10, or 10 * (9 / 5), etc, that would actually compute 9 / 5, and that's just 1 because C does integer division if both arguments are integers
cloud pasture
so if one is integer and the other is float ?
barren cradle
then it converts the integer to a floating point number
cloud pasture
so after running it with faktor as double it still runs in my terminal that -30 Grad celsius is 298.00 Fahrenheit = ts+ 1 * x * faktor but in my calculations -30.0 +1 * 10.0* 9.0/5.0 +32.0 does not equal that
barren cradle
what's the type of faktor?
cloud pasture
double
barren cradle
hmm can you show the code?
as text in 3 backticks, not as a screenshot
like this:
```c
the code
```
cloud pasture
ts = -40.0;
float x;
x = 10.0;
double faktor;
faktor = 9.0/5.0 + 32.0;
printf("\nTemperatur in verschiedenen Einheiten :\nIn Grad Celsisus In Fahrenheit");
printf("\n%fGrad Celsius | %.2f Fahrenheit",ts+ 1* x, ts+ 1 * x * faktor); ````ah that's just because x is 10, and 10.0 * 9.0 / 5.0 is actually an integer
(as in, it still has type double, but the number is an integer)
so that's the correct result for this formula
by the way, float ts should be double ts, and you can initialize a variable right where you create it: ```diff
cloud pasture
ah okay, but how is the code saying 298.00 for -30 degree but if i put it exactly like i did in my code in my calculator its a different number
barren cradle
ah also I don't think this equation is correct
cloud pasture
yeah but where
echo python
i think the + 32
cloud pasture
im trying to figure out what went wrong but i cant see it
barren cradle
you want the factor to be 9.0 / 5.0, and then add +32 to the result
although I think you need to subtract 32, not add it?
ah wait no nevermind
echo python
barren cradle
yeah
cloud pasture
ah so 32 is just meant to be added to the overall result of my faktor 9/5 and not be part of the faktor?
barren cradle
yup
echo python
But what is the -40?
cloud pasture
so i would either have to integer 32 or just add it to the end but would that be the same?
echo python
Just as example
const double X = 10.0;
const double FAKTOR = 9.0/5.0;
const double ADD = 32.0;
void print(const int number)
{
double grad = number * X;
double fahrenheit = number * X * FAKTOR + ADD;
printf("\n%.2f Grad Celsius %.2f Fahrenheit", grad, fahrenheit);
}
int main()
{
for (int i = 0; i < 12; i++)
{
print(i);
}
}```beginning of tabelle
barren cradle
You could also write a function instead of using multiple times printf. But both...
^ I think this is a very good point. You should write a function that takes a temparature in celsius and converts it to a temperature in fahrenheit
barren cradle
so i would either have to integer 32 or just add it to the end but would that be...
you need to add it at the end
I think they want to have the temperatures -40, -30, -20, etc, celsius
and convert those to fahrenheit
so I would add one function that does the conversion betwen celsius and fahrenheit
it doesn't care about X because that's part of how you calculate the number to convert
echo python
-4 - 7 works
cloud pasture
Hinweis: Sie dürfen keine Schleifen verwenden. Versuchen Sie, möglichst nicht mit festen Werten zu arbeiten, so dass das Programm flexibel an einer Stelle für Start- und Endwert sowie Schrittweite für die Temperatur abgeändert werden kann.
echo python
Hinweis: Sie dürfen keine Schleifen verwenden. Versuchen Sie, möglichst nicht mi...
was zur hölle haha
barren cradle
yeah so that means you should write a conversion function
echo python
Yeah then just call the function multiple times
cloud pasture
😭
echo python
Hinweis: Sie dürfen keine Schleifen verwenden. Versuchen Sie, möglichst nicht mi...
The end is kinda confusing lol
What does he want
Without loops
cloud pasture
x = 10 in my code is schrittweite für temp, he wants that can be changed
i i want jumps of + 20 then my code should do that instead of 10 but still be right
echo python
yeah and the startwert is also flexible. So it should be fine
cloud pasture
my prof wants me to do things he never even spoke about or in the papers he gave us
echo python
Normal prof moment
cloud pasture
he couldnt even help me in the first place with the code i had first
echo python
lol
I had the same issue in the berufsausbildung
Now i study and the profs are competent
cloud pasture
all he gave us is a link to wikibooks
echo python
nice
cloud pasture
i read 1 example and still dont know anything
cloud pasture
only c
echo python
rip bro
echo python
you will see. Dies in memory leakage
cloud pasture
nice
echo python
You have to do all by yourself. But maybe if u only do C its okay
cloud pasture
🙂
cloud pasture
ive sit at this simple task for overall 3 hours now i think
fun.
now tomorrow i gotta read something about how to do functions and watch videos but atleast i got help thank you guys👍
echo python
np
cloud pasture
!solved