How can I use a delimter to take sevral variables from the same input

[bojomojo]

Hello
I need the user to input for example a time format HH:MM(AMorPM) or a complex number format: X+jY

Then I want to read HH in and int and MM in another int
and the same for the complex number example.

I am aware I should use delimiters, but i dont know what to do, any help will be appreciated

[daviddoria]

I believe this is generally called tokenizing? Take a look at this -
http://www.daniweb.com/forums/thread27905.html

Is that what you were asking?

[ArkM]

Look at the time input validation stuff and try to adopt it for complex number input (and other user types):

struct Time {
    int hh, mm;
    std::string ampm; // "AM" or "PM"
};

bool getTime(std::istream& is, Time& t)
{
    bool res = false;
    char c;
    if (is >> t.hh) { // true if it's a number
        if (is.get(c) && c == ':' && (is >> t.mm)) { // :MM here
            if ((is >> t.ampm) && (t.ampm == "AM" || t.ampm == "PM")) {
                // Check up hh & mm values
                if (t.hh >= 0 && t.hh <= 12 && t.mm >= 0 && t.mm < 60)
                    res = true; // good time value
            }
        }
    } 
    return res;
}
// Advanced (syntax sugar):
std::istream& operator>>(std::istream& is, Time& t) {
    if (!getTime(is,t))
        is.setstate(std::ios::failbit);
    return is;
}
std::ostream& operator<<(std::ostream& os, const Time& t) {
    os << t.hh << ':' << t.mm << ' ' << t.ampm;
    return os;
}

However this approach has a serious defect in the console input environment. If the user types a part of a valid time value only then getTime waits the rest of Time value. It seems like you program hangs. Possible workaround: read a line then use istringstream:

bool GetTime(Time& t)
{
    bool res = false;
    std::string line;
    if (std::getline(std::cin,line)) {
        std::istringstream is(line);
        res = getTime(is,t);
    }
    return res;
}

Of course, it's not a reference implementation. Sorry but I have no time to prepare Program Logic Manual for this improvisation ;)...

[bojomojo]

I had that first method in a book.

But i have a question:
how does the program know how many characters are hh and mm and so on

we fist tell it if(cin>>hh) will that work whether the user inputs 10:40 or 2329:40?

I will check for it to be between 0 and 12, but the thing I mean is how can it tell that it will stop before the ":"

[iamthwee]

Another option would be to use boost libraries and regex to evaluate a correct time. It would save a lot of messing around as ArkM has demonstrated. :P

For example:
http://binaryelves.wordpress.com/2008/08/28/regular-expressions-time-hhmm-validation-24-hours-format/

[bojomojo]

Another option would be to use boost libraries and regex to evaluate a correct time. It would save a lot of messing around as ArkM has demonstrated. :P

For example:
http://binaryelves.wordpress.com/2008/08/28/regular-expressions-time-hhmm-validation-24-hours-format/

I am not doing it for the time, I want to learn the method, the time is just an example.

Would appreciate if someone tell me what tells the program to stop reading hh before the delimiter when i use

if (cin>>hh>

[iamthwee]

Nah look at the link below kiddo:
http://www.daniweb.com/forums/post140537-2.html

Then you separate them into to arrays.

array[0]
array[1]

Then go through all the rules, so you ensure you get valid times.

[bojomojo]

Nah look at the link below kiddo:
http://www.daniweb.com/forums/post140537-2.html

okay, this is alot easier, but this will get all of them as strings, i want to be able to extract some as strings, some as chars and some as intergers and doubles
and i also want them to be into different variables, not just one, like token for example

and is the std:: instead of using namespace std ??

[bojomojo]

okay, i dont get the last part you added to your post, about the arrays, how can i extract different types as I specified, and keep them in different variables

[iamthwee]

Pretty simple really, to convert a string to an int etc, just use stringstreams.

http://faq.cprogramming.com/cgi-bin/smartfaq.cgi?answer=1046996179&id=1043284385

You don't really need to use single chars here.

And if you use a vector instead of an array you just build the values on the fly as you go. Although you could use a dynamic array, but that's gay in my opinion.

[bojomojo]

okay, and what you meant by the arrays

you mean instead of the while with the token,

i make it like getlink(iss, token, :) ????

is that what you mean?
btw, i never used stringstreams, and i dont even know what is iss :)

[iamthwee]

>btw, i never used stringstreams, and i dont even know what is iss

Yeah well, you learn something new tous le jour and such and such.

[bojomojo]

yes, i agree, but you didnt answer my question about the arrays

[iamthwee]

Well personally I'd use a vector:

vissssssssssssssssssss

#include <iostream>
#include <vector>
#include <string>
#include <sstream>

using namespace std;

int main()
{

   vector <string> array; 
 
   string tmp = "12:20";
   string token;
   istringstream iss(tmp);
   while ( getline(iss, token, ':') )
   {
      array.push_back(token);
   }   
   cout <<array[0] <<endl;
   cout <<array[1] <<endl;
   
   cin.get();
}

[bojomojo]

i think i will have to

vector<int> array

in order for that to work, correct?

[iamthwee]

I guess, but I'm just conjecturing here.

I was thinking you might get into trouble with times such as "03:45" but maybe stringstream converts the "03" to 3 anyhoo.

Don't quote me on that.

[bojomojo]

very good,

but i am not quite getting istringstream, i got its to input the stream, and does iss has anything to do with it?

[iamthwee]

Post your code...

[bojomojo]

what code?
I mean the one you made, this one:

#include <iostream>
#include <vector>
#include <string>
#include <sstream>

using namespace std;

int main()
{

   vector <string> array; 
 
   string tmp = "12:20";
   string token;
   istringstream iss(tmp);
   while ( getline(iss, token, ':') )
   {
      array.push_back(token);
   }   
   cout <<array[0] <<endl;
   cout <<array[1] <<endl;
   
   cin.get();
}

[iamthwee]

Is that a joke? No the bit where you're not quite getting the istringstream?

Post an example of what you've tried, state what you expect, and what you're unsure of.

[bojomojo]

by "I am not getting istringstream"

I mean i dont understand it, and i dont know what it does.

[ArkM]

>how does the program know how many characters are hh and mm and so on
>we fist tell it if(cin>>hh) will that work whether the user inputs 10:40 or 2329:40?
>I will check for it to be between 0 and 12, but the thing I mean is how can it tell that it will stop before the ":"
The overloaded operator>>(istream&,int&) stops to extract characters from a stream when integer representation ended. Obviously, the colon is not a part of integer. That's all. The next get(char&) extracts stop-char and we can compare it with desired colon char.
We will check hours and minutes after input operations ended (see line #14 in my snippet above):

line #14:
if (t.hh >= 0 && t.hh <= 12 && t.mm >= 0 && t.mm < 60)

>by "I am not getting istringstream" ... I mean i dont understand it, and i dont know what it does.
http://www.deitel.com/articles/cplusplus_tutorials/20060211/index.html
Well, pay attention to getTime; no stringstreams in this (working ;)) function.

You asked a general question about input data validation. Be ready to get general answers ;)...