Inputting integers with commas

[Randy Yates]

How to do? Such a simple #@%^&@ thing and I'm spending hours on it.

For example,

long mynum;

istringstream mystr("380,900", istringstream::in);
mystr >> mynum;
cout << mynum;

yields "380".

I've tried setting the locale of mystr,

mystr.imbue(locale("en_US"));

to various things but no joy.

Yes, I know I could iterate through and .erase the commas, but I
was hoping there was a more elegant and/or built-in solution.
--
% Randy Yates % "Bird, on the wing,
%% Fuquay-Varina, NC % goes floating by
%%% 919-577-9882 % but there's a teardrop in his eye..."
%%%% <ya***@ieee.org> % 'One Summer Dream', *Face The Music*, ELO
http://home.earthlink.net/~yatescr

[Malte Starostik]

Randy Yates schrieb:

How to do? Such a simple #@%^&@ thing and I'm spending hours on it.

For example,

long mynum;

istringstream mystr("380,900", istringstream::in);
mystr >> mynum;
cout << mynum;

yields "380".

And correctly so, you're only reading the first number ;-)
Apart from that you could just read the comma into a char:
char c;
long mynum1, mynum2;
mystr >> mynum1 >> c >> mynum2;

HTH,
Malte

[Malte Starostik]

Malte Starostik schrieb:

Randy Yates schrieb:

How to do? Such a simple #@%^&@ thing and I'm spending hours on it.
For example,

long mynum;

istringstream mystr("380,900", istringstream::in);
mystr >> mynum;
cout << mynum;

yields "380".

And correctly so, you're only reading the first number ;-)

Sorry, I gather that comma is not supposed to separate individual
numbers but a thousand separator? (not used to that, in my de_DE locale
the thousand separator is a . while a decimal point is a ,)
In that case maybe something like this:

long mynum;
istringstream mystr("380,900", istringstream::in);
for ( mynum = 0; mystr; )
{
long tmp;
if (mystr >> tmp) mynum += tmp;
char c;
if (mystr >> c && c == ',' ) mynum *= 1000;
}
cout << mynum << endl;

The error checking is quite suboptimal though and it reads things like
380,-900 as 379100, 380,1,0 as 380001000 etc.

Regards,
Malte

[Randy Yates]

Malte Starostik <ma*************@t-online.de> writes:

Randy Yates schrieb:

How to do? Such a simple #@%^&@ thing and I'm spending hours on
it. For example,
long mynum;
istringstream mystr("380,900", istringstream::in);
mystr >> mynum;
cout << mynum;
yields "380".
And correctly so, you're only reading the first number

I see. So when your boss emails you and asks

"Hey Malte, please order 1,173 T-Shirts for the company picnic",

you say,

"Hey boss, which is it, 1 or 173?"

;(
;-) Apart from that you could just read the comma into a char:
char c;
long mynum1, mynum2;
mystr >> mynum1 >> c >> mynum2;
As I said, I know there are ways AROUND it - I was looking for the
elegant/proper way.
HTH,
Not really.
Malte

--
% Randy Yates % "Maybe one day I'll feel her cold embrace,
%% Fuquay-Varina, NC % and kiss her interface,
%%% 919-577-9882 % til then, I'll leave her alone."
%%%% <ya***@ieee.org> % 'Yours Truly, 2095', *Time*, ELO
http://home.earthlink.net/~yatescr

[E. Robert Tisdale]

Randy Yates wrote:

How to do? Such a simple #@%^&@ thing and I'm spending hours on it.

For example,

long mynum;

istringstream mystr("380,900", istringstream::in);
I suppose that 380,900 represents 380900?
mystr >> mynum;
cout << mynum;

yields "380".

I've tried setting the locale of mystr,

mystr.imbue(locale("en_US"));

to various things but no joy.

Yes, I know I could iterate through and .erase the commas, but I
was hoping there was a more elegant and/or built-in solution.

Nope.

[Randy Yates]

Malte Starostik <ma*************@t-online.de> writes:

Malte Starostik schrieb:

Randy Yates schrieb:

How to do? Such a simple #@%^&@ thing and I'm spending hours on it.
For example,

long mynum;

istringstream mystr("380,900", istringstream::in);
mystr >> mynum;
cout << mynum;

yields "380".

And correctly so, you're only reading the first number ;-)

Sorry, I gather that comma is not supposed to separate individual
numbers but a thousand separator? (not used to that, in my de_DE
locale the thousand separator is a . while a decimal point is a ,)
In that case maybe something like this:

long mynum;
istringstream mystr("380,900", istringstream::in);
for ( mynum = 0; mystr; )
{
long tmp;
if (mystr >> tmp) mynum += tmp;
char c;
if (mystr >> c && c == ',' ) mynum *= 1000;
}
cout << mynum << endl;

The error checking is quite suboptimal though and it reads things like
380,-900 as 379100, 380,1,0 as 380001000 etc.

Thanks, that helps (if there is no "right" way to do it).
--
% Randy Yates % "I met someone who looks alot like you,
%% Fuquay-Varina, NC % she does the things you do,
%%% 919-577-9882 % but she is an IBM."
%%%% <ya***@ieee.org> % 'Yours Truly, 2095', *Time*, ELO
http://home.earthlink.net/~yatescr

[Randy Yates]

"E. Robert Tisdale" <E.**************@jpl.nasa.gov> writes:

Randy Yates wrote:

How to do? Such a simple #@%^&@ thing and I'm spending hours on
it. For example,
long mynum;
istringstream mystr("380,900", istringstream::in);

I suppose that 380,900 represents 380900?

mystr >> mynum;
cout << mynum;
yields "380". I've tried setting the locale of mystr,
mystr.imbue(locale("en_US"));
to various things but no joy.
Yes, I know I could iterate through and .erase the commas, but I
was hoping there was a more elegant and/or built-in solution.

Nope.

I can understand that. Converting human-readable numeric strings to
integers is not that common of a task.
--
% Randy Yates % "Ticket to the moon, flight leaves here today
%% Fuquay-Varina, NC % from Satellite 2"
%%% 919-577-9882 % 'Ticket To The Moon'
%%%% <ya***@ieee.org> % *Time*, Electric Light Orchestra
http://home.earthlink.net/~yatescr

[Adrian]

"Randy Yates" <ya***@ieee.org> wrote in message
news:wt**********@ieee.org...

How to do? Such a simple #@%^&@ thing and I'm spending hours on it.

For example,

long mynum;

istringstream mystr("380,900", istringstream::in);
mystr >> mynum;
cout << mynum;

yields "380".

Having done some reading I think num_get is what you need but at the moment
I am struggling to make it work.

Probably no help whatsoever

Adrian

[Siemel Naran]

"Randy Yates" <ya***@ieee.org> wrote in message
news:wt**********@ieee.org...

istringstream mystr("380,900", istringstream::in);
mystr >> mynum;
cout << mynum;

yields "380".

Haven't done this myself. But I think one uses the numpunct facet. My
approach would be:
[ ] create a class standardnumpunct derived from numpunct<char> and override
the appropriate member functions -- at least do_grouping to return
std::string(1,3), which is the string of one char(0x03). I think you need
just this one function.
class standardnumpunct : public std::numpunct<char> {
protected:
string_type do_grouping {
return std::string(1,3);
}
};

[ ] create a new locale as follows
std::locale groupinglocale(std::locale(), new standardnumpunct);

[ ] imbue your istringstream mystr with this locale. there is no need to
delete the new standardnumpunct, as the destructor of groupinglocale will do
this for us.
mystr.imbue(groupinglocale);
My post "Re: convert hex to oct" on April 02, 2004 might be helpful. Let us
know if you get it to work.

[Karl Heinz Buchegger]

Malte Starostik wrote:

Sorry, I gather that comma is not supposed to separate individual
numbers but a thousand separator? (not used to that, in my de_DE locale
the thousand separator is a . while a decimal point is a ,)
In that case maybe something like this:

long mynum;
istringstream mystr("380,900", istringstream::in);
for ( mynum = 0; mystr; )
{
long tmp;
if (mystr >> tmp) mynum += tmp;
char c;
if (mystr >> c && c == ',' ) mynum *= 1000;
}
cout << mynum << endl;

The error checking is quite suboptimal though and it reads things like
380,-900 as 379100, 380,1,0 as 380001000 etc.

I would do:

Take the input string, remove all ',' characters:

#include <iostream>
#include <string>
#include <sstream>
#include <algorithm>
using namespace std;

bool IsComma( char c )
{
return c == ',';
}

int main()
{
string Input = "380,900";
remove_if( Input.begin(), Input.end(), IsComma );
istringstream mystr(Input);

int mynum;

mystr >> mynum;
cout << mynum;
}

--
Karl Heinz Buchegger
kb******@gascad.at

[Malte Starostik]

Karl Heinz Buchegger schrieb:

I would do:

Take the input string, remove all ',' characters:

bool IsComma( char c )
{
return c == ',';
}

string Input = "380,900";
remove_if( Input.begin(), Input.end(), IsComma );

Very nice, except this should be:
Input.erase( remove_if( Input.begin(), Input.end(), IsComma ),
Input.end() );

As remove_if doesn't actually remove anything.

Regards,
Malte