How to read in user entered comma separated integers?

Question

I\'m writing a program that prompts the user for:

1. Size of array
2. Values to be put into the array

First part is fine, I create a dynamica

Answer 1

A priori, you should want to check that the comma is there, and declare an error if it's not. For this reason, I'd handle the first number separately:

std::vector dest;
int value;
std::cin >> value;
if ( std::cin ) {
    dest.push_back( value );
    char separator;
    while ( std::cin >> separator >> value && separator == ',' ) {
        dest.push_back( value );
    }
}
if ( !std::cin.eof() ) {
    std::cerr << "format error in input" << std::endl;
}

Note that you don't have to ask for the size first. The array (std::vector) will automatically extend itself as much as needed, provided the memory is available.

Finally: in a real life example, you'd probably want to read line by line, in order to output a line number in case of a format error, and to recover from such an error and continue. This is a bit more complicated, especially if you want to be able to accept the separator before or after the newline character.