Manipulating user input

**Mike Wahler** · Jul 22 '05, 08:40 AM

Re: Manipulating user input

"agent349" <agent349@yahoo .com> wrote in message
news:e23997a6.0 404082133.70087 8a0@posting.goo gle.com...[color=blue]
> Hi,
>
> I'm fairly new to c++. I need user input in the form of dollar
> amounts, ie: "$10.00". I'd like to remove the dollar sign "$" then
> store the rest in a variable. How do I go about removing the dollar
> sign? Thanks in advance![/color]

std::string input;
int amount(0);

std::getline(st d::cin, input);
if(!input.empty ())
{
std::istringstr eam iss(input.subst r(1));
iss >> amount;
}

std::cout << '$' << amount / 100 << '.' << amount % 100 << '\n';

-Mike

**Mike Wahler** · Jul 22 '05, 08:40 AM

Re: Manipulating user input

"agent349" <agent349@yahoo .com> wrote in message
news:e23997a6.0 404082133.70087 8a0@posting.goo gle.com...[color=blue]
> Hi,
>
> I'm fairly new to c++. I need user input in the form of dollar
> amounts, ie: "$10.00". I'd like to remove the dollar sign "$" then
> store the rest in a variable. How do I go about removing the dollar
> sign? Thanks in advance![/color]

std::string input;
int amount(0);

std::getline(st d::cin, input);
if(!input.empty ())
{
std::istringstr eam iss(input.subst r(1));
iss >> amount;
}

std::cout << '$' << amount / 100 << '.' << amount % 100 << '\n';

-Mike

**John Harrison** · Jul 22 '05, 08:40 AM

Re: Manipulating user input

"Mike Wahler" <mkwahler@mkwah ler.net> wrote in message
news:%2rdc.2855 $A_4.2826@newsr ead1.news.pas.e arthlink.net...[color=blue]
>
> "agent349" <agent349@yahoo .com> wrote in message
> news:e23997a6.0 404082133.70087 8a0@posting.goo gle.com...[color=green]
> > Hi,
> >
> > I'm fairly new to c++. I need user input in the form of dollar
> > amounts, ie: "$10.00". I'd like to remove the dollar sign "$" then
> > store the rest in a variable. How do I go about removing the dollar
> > sign? Thanks in advance![/color]
>
> std::string input;
> int amount(0);
>
> std::getline(st d::cin, input);
> if(!input.empty ())
> {
> std::istringstr eam iss(input.subst r(1));
> iss >> amount;
> }
>
> std::cout << '$' << amount / 100 << '.' << amount % 100 << '\n';
>
> -Mike
>[/color]

I think you are forgetting the period in the input.

john

**John Harrison** · Jul 22 '05, 08:40 AM

Re: Manipulating user input

"Mike Wahler" <mkwahler@mkwah ler.net> wrote in message
news:%2rdc.2855 $A_4.2826@newsr ead1.news.pas.e arthlink.net...[color=blue]
>
> "agent349" <agent349@yahoo .com> wrote in message
> news:e23997a6.0 404082133.70087 8a0@posting.goo gle.com...[color=green]
> > Hi,
> >
> > I'm fairly new to c++. I need user input in the form of dollar
> > amounts, ie: "$10.00". I'd like to remove the dollar sign "$" then
> > store the rest in a variable. How do I go about removing the dollar
> > sign? Thanks in advance![/color]
>
> std::string input;
> int amount(0);
>
> std::getline(st d::cin, input);
> if(!input.empty ())
> {
> std::istringstr eam iss(input.subst r(1));
> iss >> amount;
> }
>
> std::cout << '$' << amount / 100 << '.' << amount % 100 << '\n';
>
> -Mike
>[/color]

I think you are forgetting the period in the input.

john

**John Harrison** · Jul 22 '05, 08:40 AM

Re: Manipulating user input

"agent349" <agent349@yahoo .com> wrote in message
news:e23997a6.0 404082133.70087 8a0@posting.goo gle.com...[color=blue]
> Hi,
>
> I'm fairly new to c++. I need user input in the form of dollar
> amounts, ie: "$10.00". I'd like to remove the dollar sign "$" then
> store the rest in a variable. How do I go about removing the dollar
> sign? Thanks in advance![/color]

What sort of variable? int, double, some custom money type?

Integer variables are the best for manipulating money, just count you money
in cents, and then convert to dollars when you have to output figures. A
typical newbie error is 'money prints with a period, therefore I must use a
double or a float because they print with periods'. That is an error, money
is an integral quantity, you only ever have a whole number of cents,
therefore integers are the correct thing to use. How you print a money total
has got nothing to do with it.

There are lots of ways to do what you want, here's one way. It works but it
may not do exactly what you want since your requirements are not clearly
defined.

#include <iostream>
#include <iomanip>
using namespace std;

int main()
{
cout << "enter some money (like this $12.34) "
char dummy1, dummy2;
int dollars, cents;
cin >> dummy1 >> dollars >> dummy2 >> cents;
int total_cents = 100*dollars + cents;

cout << "You entered $" << total_cents/100 << '.' << setfill('0') <<
setw(2) << total_cents%100 << '\n';
}

This is untested code.

The dummy1 and dummy2 variables are there just to absorb the dollar sign and
period from the input.

The last line shows how you can pretty print a money value from an int
variable which is a number of cents.

The big problem with this program is that it makes no attempt to deal with
incorrect input on the part of the user, it will accept some incorrect input
and barf on others. But you didn't specify what you wanted to happen on
incorrect input (or even what correct input was) so I ignored that issue.

john

**John Harrison** · Jul 22 '05, 08:40 AM

Re: Manipulating user input

"agent349" <agent349@yahoo .com> wrote in message
news:e23997a6.0 404082133.70087 8a0@posting.goo gle.com...[color=blue]
> Hi,
>
> I'm fairly new to c++. I need user input in the form of dollar
> amounts, ie: "$10.00". I'd like to remove the dollar sign "$" then
> store the rest in a variable. How do I go about removing the dollar
> sign? Thanks in advance![/color]

What sort of variable? int, double, some custom money type?

Integer variables are the best for manipulating money, just count you money
in cents, and then convert to dollars when you have to output figures. A
typical newbie error is 'money prints with a period, therefore I must use a
double or a float because they print with periods'. That is an error, money
is an integral quantity, you only ever have a whole number of cents,
therefore integers are the correct thing to use. How you print a money total
has got nothing to do with it.

There are lots of ways to do what you want, here's one way. It works but it
may not do exactly what you want since your requirements are not clearly
defined.

#include <iostream>
#include <iomanip>
using namespace std;

int main()
{
cout << "enter some money (like this $12.34) "
char dummy1, dummy2;
int dollars, cents;
cin >> dummy1 >> dollars >> dummy2 >> cents;
int total_cents = 100*dollars + cents;

cout << "You entered $" << total_cents/100 << '.' << setfill('0') <<
setw(2) << total_cents%100 << '\n';
}

This is untested code.

The dummy1 and dummy2 variables are there just to absorb the dollar sign and
period from the input.

The last line shows how you can pretty print a money value from an int
variable which is a number of cents.

The big problem with this program is that it makes no attempt to deal with
incorrect input on the part of the user, it will accept some incorrect input
and barf on others. But you didn't specify what you wanted to happen on
incorrect input (or even what correct input was) so I ignored that issue.

john

**David Harmon** · Jul 22 '05, 08:40 AM

Re: Manipulating user input

On Fri, 09 Apr 2004 06:05:47 GMT in comp.lang.c++, "Mike Wahler"
<mkwahler@mkwah ler.net> wrote,[color=blue]
>std::getline(s td::cin, input);
>if(!input.empt y())
>{
> std::istringstr eam iss(input.subst r(1));
> iss >> amount;
>}[/color]

Perhaps excessive?
if (cin.peek() == '$')
cin.ignore(1);

**David Harmon** · Jul 22 '05, 08:40 AM

Re: Manipulating user input

On Fri, 09 Apr 2004 06:05:47 GMT in comp.lang.c++, "Mike Wahler"
<mkwahler@mkwah ler.net> wrote,[color=blue]
>std::getline(s td::cin, input);
>if(!input.empt y())
>{
> std::istringstr eam iss(input.subst r(1));
> iss >> amount;
>}[/color]

Perhaps excessive?
if (cin.peek() == '$')
cin.ignore(1);

**Mike Wahler** · Jul 22 '05, 08:41 AM

Re: Manipulating user input

"John Harrison" <john_andronicu s@hotmail.com> wrote in message
news:c55j5c$2mt 6ki$1@ID-196037.news.uni-berlin.de...[color=blue]
>
> "Mike Wahler" <mkwahler@mkwah ler.net> wrote in message
> news:%2rdc.2855 $A_4.2826@newsr ead1.news.pas.e arthlink.net...[color=green]
> >
> > "agent349" <agent349@yahoo .com> wrote in message
> > news:e23997a6.0 404082133.70087 8a0@posting.goo gle.com...[color=darkred]
> > > Hi,
> > >
> > > I'm fairly new to c++. I need user input in the form of dollar
> > > amounts, ie: "$10.00". I'd like to remove the dollar sign "$" then
> > > store the rest in a variable. How do I go about removing the dollar
> > > sign? Thanks in advance![/color]
> >
> > std::string input;
> > int amount(0);
> >
> > std::getline(st d::cin, input);
> > if(!input.empty ())
> > {
> > std::istringstr eam iss(input.subst r(1));
> > iss >> amount;
> > }
> >
> > std::cout << '$' << amount / 100 << '.' << amount % 100 << '\n';
> >
> > -Mike
> >[/color]
>
> I think you are forgetting the period in the input.[/color]

Had to leave something for OP to do. :-)

-Mike

**Mike Wahler** · Jul 22 '05, 08:41 AM

Re: Manipulating user input

"John Harrison" <john_andronicu s@hotmail.com> wrote in message
news:c55j5c$2mt 6ki$1@ID-196037.news.uni-berlin.de...[color=blue]
>
> "Mike Wahler" <mkwahler@mkwah ler.net> wrote in message
> news:%2rdc.2855 $A_4.2826@newsr ead1.news.pas.e arthlink.net...[color=green]
> >
> > "agent349" <agent349@yahoo .com> wrote in message
> > news:e23997a6.0 404082133.70087 8a0@posting.goo gle.com...[color=darkred]
> > > Hi,
> > >
> > > I'm fairly new to c++. I need user input in the form of dollar
> > > amounts, ie: "$10.00". I'd like to remove the dollar sign "$" then
> > > store the rest in a variable. How do I go about removing the dollar
> > > sign? Thanks in advance![/color]
> >
> > std::string input;
> > int amount(0);
> >
> > std::getline(st d::cin, input);
> > if(!input.empty ())
> > {
> > std::istringstr eam iss(input.subst r(1));
> > iss >> amount;
> > }
> >
> > std::cout << '$' << amount / 100 << '.' << amount % 100 << '\n';
> >
> > -Mike
> >[/color]
>
> I think you are forgetting the period in the input.[/color]

Had to leave something for OP to do. :-)

-Mike

**Kevin Goodsell** · Jul 22 '05, 08:41 AM

Re: Manipulating user input

David Harmon wrote:
[color=blue]
> On Fri, 09 Apr 2004 06:05:47 GMT in comp.lang.c++, "Mike Wahler"
> <mkwahler@mkwah ler.net> wrote,
>[color=green]
>>std::getline( std::cin, input);
>>if(!input.emp ty())
>>{
>> std::istringstr eam iss(input.subst r(1));
>> iss >> amount;
>>}[/color]
>
>
> Perhaps excessive?
> if (cin.peek() == '$')
> cin.ignore(1);
>[/color]

I think there's a 0-argument ignore() for removing 1 character.

-Kevin
--
My email address is valid, but changes periodically.
To contact me please use the address from a recent posting.

**Kevin Goodsell** · Jul 22 '05, 08:41 AM

Re: Manipulating user input

David Harmon wrote:
[color=blue]
> On Fri, 09 Apr 2004 06:05:47 GMT in comp.lang.c++, "Mike Wahler"
> <mkwahler@mkwah ler.net> wrote,
>[color=green]
>>std::getline( std::cin, input);
>>if(!input.emp ty())
>>{
>> std::istringstr eam iss(input.subst r(1));
>> iss >> amount;
>>}[/color]
>
>
> Perhaps excessive?
> if (cin.peek() == '$')
> cin.ignore(1);
>[/color]

I think there's a 0-argument ignore() for removing 1 character.

-Kevin
--
My email address is valid, but changes periodically.
To contact me please use the address from a recent posting.

Manipulating user input

Manipulating user input

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