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# how to cut off the decimal?

printf("%lf",3.25);

the result is 3.25000

i want the answer correct to 3 decimal places

What should i do?
thanks!
Nov 15 '05 #1
8 10659
"nick" <i1********@yahoo.com>wrote:
printf("%lf",3.25);
the result is 3.25000
i want the answer correct to 3 decimal places
What should i do?
thanks!

use: .n after % and bevour f
n decimal places.

printf("%.3lf", 3,25);
^^
the result is 3.250;

Nov 15 '05 #2

Eberhard Funck wrote:

printf("%.3lf", 3,25);
^^
the result is 3.250;

I guess you thought of
printf("%.3lf", 3.25);
otherwise the result is 3.000

regards
Michael

Nov 15 '05 #3

"Michael" <mi****@gmx.net> schrieb:

Eberhard Funck wrote:

printf("%.3lf", 3,25);
^^
the result is 3.250;
I guess you thought of
printf("%.3lf", 3.25);

^ otherwise the result is 3.000

regards
Michael

Hello Michael,

Thanks for the hint.
It was my mistake with "," instead of ".".

Thanks.
Nov 15 '05 #4

Eberhard Funck wrote:
printf("%.3lf", 3,25);

[...] the result is 3.000

Hi Eberhard,
well I'm not sure if I am right with the above
statement, since the types do not match (int vs double).
Is this converted during compiling or pure luck if 3.000
is shown?
Any hints?

Thanks,
Michael

Nov 15 '05 #5

"Michael" wrote:

Eberhard Funck wrote:
printf("%.3lf", 3,25);
[...] the result is 3.000

Hi Eberhard,
well I'm not sure if I am right with the above
statement, since the types do not match (int vs double).
Is this converted during compiling or pure luck if 3.000
is shown?
Any hints?

Thanks,
Michael

Hi Michael,

I think it's pure luck.
My lcc compiler makes this warning, if I write 3,25 instead 3.25:
"Warning printf argument mismatch for format f. Expected double got int"
The result is 0.000

Eberhard

Nov 15 '05 #6
nick wrote:
printf("%lf",3.25);

the result is 3.25000

i want the answer correct to 3 decimal places

What should i do?
Short answer: open an elementary C textbook.

#include <stdio.h>

void show(double x)
{
/* note that the specifier is %f or %g, not %lf or %lg */
printf("total precision of 3 decimal places:\n %.3g\n", x);
printf("3 decimal places to right of decimal:\n %.3f\n\n", x);
}

int main(void)
{
show(3.25);
show(325);
show(.325);
show(3.2574);
show(3.2547);
return 0;
}
total precision of 3 decimal places:
3.25
3 decimal places to right of decimal:
3.250

total precision of 3 decimal places:
325
3 decimal places to right of decimal:
325.000

total precision of 3 decimal places:
0.325
3 decimal places to right of decimal:
0.325

total precision of 3 decimal places:
3.26
3 decimal places to right of decimal:
3.257

total precision of 3 decimal places:
3.25
3 decimal places to right of decimal:
3.255

thanks!

Nov 15 '05 #7
Eberhard Funck wrote:
"nick" <i1********@yahoo.com>wrote:
printf("%lf",3.25);

printf("%.3lf", 3,25);

Both of you need to know: the printf specifier for a double (or float)
is "%f".
Nov 15 '05 #8
>> printf("%.3lf", 3,25);

Both of you need to know: the printf specifier for a double (or float)
is "%f".

Thanks for correction.
Regards
Michael

Nov 15 '05 #9

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