a "temp conversion" programme

[arnuld]

i have created a new temperature conversion programme. it converts a
temperature from Fahrenheit to Celsius or from Celsius to Fahrenheit
at user's will. tell em if i need some improvements:

// conversion of temperature
// using Centigrade and Fahrenheit

#include <iostream>

int main() {
double centi;
double fahr;
char ans;

std::cout << "do you want to convert a Centigrade into Fahrenheit:
[y/n]";
std::cin >> ans;

if(ans == 'y')
{
std::cout << "Enter temperature in Centigrade: ";
std::cin >> centi;

fahr = (9.0/5.0 * centi) + 32;
std::cout << centi
<< " centigrade = "
<< fahr
<< " fahrenheit"
<< "\n";
}

else
{
std::cout << "Enter temperature in Fahrenheit: ";
std::cin >> fahr;

centi = 5.0/9.0 * (fahr - 32);
std::cout << fahr
<< " farenheit = "
<< centi
<< " centigrade"
<< "\n";
}

return 0;
}

-- arnuld
http://arnuld.blogspot.com

 

[Jacek Dziedzic]

i have created a new temperature conversion programme. it converts a
temperature from Fahrenheit to Celsius or from Celsius to Fahrenheit
at user's will. tell em if i need some improvements:

// conversion of temperature
// using Centigrade and Fahrenheit

#include <iostream>

int main() {
double centi;
double fahr;
char ans;

std::cout << "do you want to convert a Centigrade into Fahrenheit:
[y/n]";
std::cin >> ans;

if(ans == 'y')
{
std::cout << "Enter temperature in Centigrade: ";
std::cin >> centi;

fahr = (9.0/5.0 * centi) + 32;
std::cout << centi
<< " centigrade = "
<< fahr
<< " fahrenheit"
<< "\n";
}

else
{
std::cout << "Enter temperature in Fahrenheit: ";
std::cin >> fahr;

centi = 5.0/9.0 * (fahr - 32);
std::cout << fahr
<< " farenheit = "
<< centi
<< " centigrade"
<< "\n";
}

return 0;
}

Well, you could format your output better...
How about rounding to two digits after the decimal point?
That way you wouldn't get values like "3.3333333333333"
in your output.

If you are interested in achieving this, #include
the file 'iomanip' and look up on the manipulators
'fixed' and 'setprecision'.

HTH,
- J.

 

[arnuld]

Well, you could format your output better...
How about rounding to two digits after the decimal point?
That way you wouldn't get values like "3.3333333333333"
in your output.

If you are interested in achieving this, #include
the file 'iomanip' and look up on the manipulators
'fixed' and 'setprecision'.

they are for "floats". i have tried that, you can not use them for
"doubles"

 

[Jacek Dziedzic]

they are for "floats". i have tried that, you can not use them for
"doubles"

Try harder.

#include<iostream>
#include<iomanip>

using namespace std;

const double d=1.0/3.0;

int main() {
cout << fixed << setprecision(2) << d << ' '
<< setprecision(10) << d << endl;
}

HTH,
- J.

 

[=?iso-8859-1?q?Erik_Wikstr=F6m?=]

they are for "floats". i have tried that, you can not use them for
"doubles"

They should work for doubles too.

 

[arnuld]

Try harder.

#include<iostream>
#include<iomanip>

using namespace std;

const double d=1.0/3.0;

int main() {
cout << fixed << setprecision(2) << d << ' '
<< setprecision(10) << d << endl;

}

Erm... and i was using "d.precision(3)".

BTW, i removed "fixed" from your code. i does not make any difference.

 

[Jacek Dziedzic]

Erm... and i was using "d.precision(3)".

BTW, i removed "fixed" from your code. i does not make any difference.

Sure it does, you just didn't notice. I'll let you figure it out,
though. Try this

#include <iostream>
#include <iomanip>

using namespace std;

int main() {
cout << setprecision(3) << 123.456 << ' ' << fixed
<< setprecision(3) << 123.456 << endl;
}

- J.

 

[arnuld]

Sure it does, you just didn't notice. I'll let you figure it out,
though. Try this

#include <iostream>
#include <iomanip>

using namespace std;

int main() {
cout << setprecision(3) << 123.456 << ' ' << fixed
<< setprecision(3) << 123.456 << endl;

}

yes, i noticed now. the output of your programme is: 123 123.456

now here is some interesting pattern:

1.)
<< setprecision(3) << 123.456
<< fixed
<< ' '
<< setprecision(3) << 123.456


OUTPUT: 123 123.456

here i have use /fixed/ as like a prefix

2.)
<< fixed
<< setprecision(3) << 123.456
<< ' '
<< setprecision(3) << 123.456
<< endl;

OUTPUT: 123.456 123.456

here 1 /fixed/ worked for both.


3.)
<< setprecision(3) << 123.456
<< ' '
<< setprecision(3) << 123.456
<< fixed
<< endl;

}

OUTPUT: 123 123

/fixed/ doe snot work here.


i want to know how exactly /fixed/ work, in context to patterns 1,2
and 3.

?

 

[Jacek Dziedzic]

yes, i noticed now. the output of your programme is: 123 123.456

now here is some interesting pattern:

1.)
<< setprecision(3) << 123.456
<< fixed
<< ' '
<< setprecision(3) << 123.456


OUTPUT: 123 123.456

here i have use /fixed/ as like a prefix

2.)
<< fixed
<< setprecision(3) << 123.456
<< ' '
<< setprecision(3) << 123.456
<< endl;

OUTPUT: 123.456 123.456

here 1 /fixed/ worked for both.


3.)
<< setprecision(3) << 123.456
<< ' '
<< setprecision(3) << 123.456
<< fixed
<< endl;

}

OUTPUT: 123 123

/fixed/ doe snot work here.


i want to know how exactly /fixed/ work, in context to patterns 1,2
and 3.

One way would be to google for "fixed", "setprecision" and "manipulators".

Consulting your favourite C++ textbook would be another.

Anyway, fixed did not work in your last example, since it was
output _after_ your numbers. They were output already, so it had
no chance to act.

Anyway 2, with 'fixed' the 'setprecision' manipulator tells the
stream how many digits after the decimal point you want to output,
without fixed it tells how many digits _total_ you want to output.

HTH,
- J.

 

[arnuld]

One way would be to google for "fixed", "setprecision" and "manipulators".

i did that after reading your reply. sorry...

i found one more manipulator named /scientific/ an opposite of /
fixed/

Consulting your favourite C++ textbook would be another.

yes, i tried Stroustrup before posting here my 3 patterns but it did
not tell me anything useful, totally unlike Google.

Anyway, fixed did not work in your last example, since it was
output _after_ your numbers. They were output already, so it had
no chance to act.

Anyway 2, with 'fixed' the 'setprecision' manipulator tells the
stream how many digits after the decimal point you want to output,
without fixed it tells how many digits _total_ you want to output.

yes, i understood now, except one thing. from pattern '2' above, does
one /fixed/ works for all subsequent /setprecision(s)/

?

HTH,

of course that helped

 

[Jacek Dziedzic]

i did that after reading your reply. sorry...

i found one more manipulator named /scientific/ an opposite of /
fixed/

Almost an opposite. In fact you have three modes -- the default
(not fixed and not scientific), fixed and scientific.

yes, i understood now, except one thing. from pattern '2' above, does
one /fixed/ works for all subsequent /setprecision(s)/

Yes, as long as they are on the same output stream.

HTH,
- J.

 

[arnuld]

arnuld wrote:

Almost an opposite. In fact you have three modes -- the default
(not fixed and not scientific), fixed and scientific.


Yes, as long as they are on the same output stream.

thanks Jacek