Help is needed in a assigment "Strings"

[Lola02]

1) Declare a new string named "dataSource" that has the following value:

"I wonder how they extract e-mails such as [e-mail] or [e-mail], or [e-mail] from a string of words?"

2) Create a C++ program that will extract the e-mail addresses from the dataSource string.

3) Display the extracted e-mail addresses from the user

4.Add appropriate C++ Comments to explain the logic behind your chosen method for solving the problem. Comments are also helpful for the reference of future programmers, and for you.

5. Use the appropriate data types, variables, and constant variables to solve the program

[CptJY]

split the string in strings using the ' ' as separator.
then search for @. if you have it, its an email address

Give us some code so we can help

[LA48b7Xj]

Here is a crude way to do it...

#include <algorithm>
#include <iostream>
#include <string>
#include <sstream>

using namespace std;

bool is_email(const string& s)
{
    return s.find('@') != string::npos && s.find('.') != string::npos;
}

int main()
{
    const string dataSource = "I wonder how they extract e-mails such as [e-mail] "
                              " or [e-mail], or [e-mail] from a string of words?";

    stringstream ss {dataSource};
    string extract;

    while(ss >> extract)
    {
        if(is_email(extract))
            cout << extract << '\n';
    }
}

[integralfx]

You asked for it:

#include <iostream>
#include <regex>
#include <string>

int main()
{
    std::string datasource{ "I wonder how they extract e-mails such as [e-mail] or [e-mail], or [e-mail] from a string of words?" };
    std::smatch matches{};
    std::regex regex{ "[[:alnum:]]+@[[:alnum:]]+\.[[:alnum:]]+" };
    
    while( std::regex_search( datasource, matches, regex ) ) {
        std::cout << matches.str( ) << "\n";
        datasource = matches.suffix( ).str( );
    }
}

[e-mail]
[e-mail]
[e-mail]

[Lola02]

Thanks for everyone that replied really appreciate it

this what i have
#include <iostream>
#include <string>
#include <algorithm>
using namespace std;

int main()
{
string email = "";
string dataSource = "I wonder how they extract e-mails such as [e-mail], [e-mail], [e-mail] or [e-mail], or [e-mail] from a string of words?";
int atLoc = 0, beginspace = 0, trailspace = 0, length = 0, counter = 0;
int atOccurances = std::count(dataSource.begin(), dataSource.end(), '@');
cout << atOccurances << " email addresses found in the following data:\n\n" << dataSource << "\n\nThe email addresses were:\n\n";
do{
atLoc = dataSource.find('@',atLoc+counter);
beginspace = dataSource.rfind(" ",atLoc)+1;
trailspace = dataSource.find(" ",atLoc);
length = trailspace - beginspace;
email = dataSource.substr(beginspace, length + 1);
for(int i=0; i < length;i++) //outputs email and removes any trailing invalid character
{
if(i == length -1 && isalpha(email[i]) == false)
break;
else
cout << email[i];
}
cout << endl;
counter++;
}while(atOccurances>counter);

}