I'm rather new to C++ and don't really know much about it. I want a solution where the user could type in something like this (on separate lines):
AAA
BBB
CCC
And store it in a variable like this:
AAABBBCCC
Each of the lines in the input are a separate cin. There is only one variable that will store all of this. Is it possible?
Did you mean that 1 variable will store the result, or use just 1 variable throughout the whole program? If you meant the first one, given your inputs res will have AAABBBCCC at the end of the run:
std::string tmp;
std::string res;
for (int i = 0; i < 3; i ++) {
std::cin >> tmp;
res += tmp;
}
std::cout << res << std::endl;
You can just write res += tmp because std::string overloads the operator +=.
If you want user to enter the strings interactively, or if you want to read the strings from a file, then you can use the below method
#include <iostream>
#include <vector>
#include <numeric>
int main()
{
std::vector<std::string> v;
std::string s;
// Enter Ctrl-Z to terminate
while(std::cin >> s) {
v.push_back(s);
}
auto all = std::accumulate(v.begin(), v.end(), std::string(""));
std::cout << all << std::endl;
}
AAAA
DDDD
BBBB
CCCC
^Z
AAAADDDDBBBBCCCC
std::accumulate takes a binary predicate as its last argument. If you wish to add a separator between strings you can take advantage of this.
// define a delimiter
std::string delim{"-"};
// lambda to concatenate string with a separator
auto addDelimiter = [=](const std::string& s1, const std::string& s2) {
std::string result{s1};
if(!s1.empty() && !s2.empty())
result += delim;
result += s2;
return result;
};
auto all2 = std::accumulate(v.begin(), v.end(), std::string(""), addDelimiter);
std::cout << all2 << std::endl;
AAAA
BBBB
CCCC
DDDD
^Z
AAAA-BBBB-CCCC-DDDD
